In the last decade or so, the growth and development of infants and young children has become the focus of attention. In addition to physical growth, attention has also been paid to the neuropsychological and psychological development of children and to early comprehensive development and education. As a result, neuropsychological and psychological development assessment and monitoring have been carried out, and screening for developmental abnormalities has been carried out for early detection of developmental abnormalities and developmental disorders. Neuropsychiatric and psychological development in infancy and early childhood is mainly manifested in motor, language, cognitive, adaptive and social behavior, perception, and non-intelligent factors. The functional development of each aspect is an orderly, continuous and gradual process of continuous functional differentiation and maturation. The earlier development is a prerequisite for the later development, and the later development is based on the earlier development. Moreover, there is a critical period (i.e., sensitive period) for the development of each ability. All kinds of mental activities (including speech, perception, attention, emotion, memory, learning, imagination, thinking, volitional action, self-awareness, and personality traits, etc.) begin to occur in the infancy and early childhood period after birth. The specific process of development and performance varies from simple, passive, fragmented and concrete to more complex, abstract and active development and gradual system development, which is a process of immaturity to maturity, becoming more and more perfect and complex. The different stages of infancy and early childhood have key evaluation contents. In 0-1 years old, we mainly observe infants’ motor ability, sleep condition, emotional characteristics, etc.; in 1-2 years old, we mainly evaluate the level of motor skills, language, social behavior, perception and other abilities; in 2-3 years old, in addition to evaluating the above maturity level and skills, we also need to pay attention to attention ability, habitual behavior, etc. I. Development of motor function The developmental characteristics and level of motor function in infancy and early childhood can accurately reflect the development of the nervous system, and is also the basis for objectively evaluating the level of development of the central nervous system related to motor function. Developmental lags in motor development in infancy and early childhood, especially those with milestones, are considered to be sensitive indicators of developmental problems in children. The development of movement in early childhood can influence the development of their intelligence, emotions, and personality. Motor function is expressed in terms of motor ability, reflexes, posture, and postural reflexes (function) as well as proficiency in movement (skill). The nervous system regulates the gradual improvement of primitive skills into new ones. With the gradual maturation of the development of the nervous system, the reflexes, postures, postural reflexes and other motor functions of children show certain characteristics and patterns, namely: (1) the pattern of development from head to tail. For example, the head starts vertically first before the development of sitting and standing position. (2) The law of development from the proximal to the distal end. For example, in the prone position, there is shoulder and elbow support first, followed by hand support; there is swinging of the upper arm, flexion and extension of the elbow and wrist before the appearance of fine motor of the fingers. (3) The rule of whole-body movement to separate movement. For example, newborn movement is mainly whole body movement, and after 3-4 months, there are proximal joint and distal joint movements. (4) The pattern of development from reflex to random movement. The early movements of newborns and infants are reflexive and non-random, for example, from the grip reflex to the random grasping action after 4 months of age. (5) The pattern of gross motor to fine motor development. From whole hand grasping at 4 months of age to thumb-index finger-to-finger fine motor after 7 months of age. The normal development of movement in infants and toddlers depends on the interaction of intrinsic motivation, perception, physical fitness, physiological function, maturation of neurological and motor system functions, and benign stimulation of the environment. During infancy and early childhood, opportunities for motor learning can be provided to promote the development of motor skills according to the laws and sequence of motor development. Abnormal motor development refers to the development of motor development in the process of motor development is backward or abnormal movement, common motor development abnormalities are: motor development delay, cerebral palsy, motor skills disorders, etc. Delayed motor development refers to motor development in infancy and early childhood that lags behind that of children of the same age, as evidenced by a lag in the development of fine or gross motor development. It may have multiple regressions. Motor skill disorders are specific motor developmental disorders that occur in preschool and school-age years and are characterized by significant impairment in motor function in terms of coordination. Focusing on children at risk for developmental motor coordination disorders and motor developmental delays that occur during infancy is key to early detection of motor skill disorders. Cerebral palsy is a syndrome of central motor impairment due to non-progressive brain injury from prenatal to developmental period (within the first year of life). The main manifestations are central motor deficits and postural abnormalities. Early intervention can reduce the occurrence and severity of cerebral palsy. Infancy is a period of rapid development of the whole body and the brain, and growth and development are closely related to sleep, in addition to congenital, genetic factors, nutritional status, and living and raising environment. Sleep is an important physiological process that promotes the growth and development of children. Studies have confirmed that good sleep quality (including sufficient sleep time and complete sleep structure) plays a vital role in early brain development and physical development in infancy and early childhood. As we age, the sleep structure changes and sleep patterns mature. From newborn’s active sleep and quiet sleep to infancy has been divided into 4 stages (i.e., stage 1 is the light sleep period. The second stage is the middle sleep period, which is unresponsive to external stimuli. The third and fourth stages are deep sleep), rapid eye movement sleep and non-rapid eye movement sleep; sleep time also changes, with less sleep time, less rapid eye movement sleep, and longer continuous sleep time. Sleep problems are also more common in infancy and early childhood than in older children. Common sleep disorders in infancy and early childhood include sleep-related disorders, circadian rhythm disturbances, sleep disturbances, night awakenings, night terrors, nocturnal head shaking, dream demons, sleep apnea, and sudden infant death syndrome. Older children with neuropsychological problems may have shown sleep abnormalities in infancy and early childhood. Language development is also related to the maturity of neurological functions. The main cortical areas associated with language development in infants and young children are: the speech-sensory center in the posterior superior frontal gyrus of the left cerebral hemisphere, and the speech-motor center in the posterior inferior frontal gyrus of the left cerebral hemisphere. The development of speech in infants and young children generally passes through three developmental stages: the pre-language period (0-1 year); the word-sentence period (1-1.5 years), and the multi-word-sentence period (1.5-3.5 years). 5-3.5 years old). In early childhood, various causes of structural damage or dysfunction related to language perception disorders or deficits, central connections and processing, and expression of speech can lead to language developmental dysfunctions. The common causes of language development disorders are as follows: (1) mental retardation; (2) cerebral palsy; (3) hearing impairment; (4) disorders of the organ of construction; (5) autism spectrum disorders; and (6) psychosocial deprivation. The impact of brain damage on language development and functional prognosis varies among children at different ages, from 0 to 18 months of age, when the language center is not yet established and localized,. In children between 0 and 18 months of age, the language center has not yet been established and localized, and about 50% of cases have no major impact on language development when one side of the brain is damaged, and the other 50% have delayed language development but can eventually develop normally or close to normal; in children between 18 and 36 months of age, when the dominant hemisphere is damaged, the language function that has been acquired can be completely lost, but it can be compensated for by the nondominant hemisphere, and it takes about 6-12 months to rebuild language function. Attachment has been shown in early infant behaviors such as crying, asking for proximity, following, and skin-to-skin contact, and as they grow older, they will seek, depend, and pamper to obtain care or emotional needs and expect their needs and emotions to be noticed and responded to. Attachment increases the emotional connection with the nurturer, and in the interaction with the nurturer, the infant becomes aware that the nurturer can meet his or her various needs and desires, thus developing trust in them and establishing an initial interactive, benign interpersonal relationship. Among the nurturers, the mother and father are the most influential and cannot be replaced by other roles. The basis of the infant’s social development is the establishment of attachment feelings. The formation and development of attachment is divided into four stages: pre-attachment period, attachment building period, attachment relationship clarification period, and purposeful and coordinated partnership. In early parent-child and attachment relationships, the formation and development of self-awareness depends on the attitudes and parenting styles of the mother and other nurturers. Attachment provides children with comfort and security, and security and comfort in early childhood are essential for successful psychological development, both for stable and balanced personality development and for intellectual development. When certain causes affect and interfere with the formation of attachment in children, the child will show abnormalities in emotions and behavior, resulting in attachment disorders in children. Some infants who do not form attachments early in life may not grow up to be able to get along and communicate well with others. Attachment deficits in children are mostly manifested in early childhood and may be early manifestations of mental developmental disorders (such as mental retardation and autism spectrum disorders), which require timely detection and early intervention. The early training of attentional skills begins to develop in early infancy, with attention to objects in front of the eyes starting at 1 month of age, and the duration of gaze increases with age. Attention is divided into unintentional and intentional attention. Unintentional attention is attention that occurs naturally and does not require volitional effort, and attention before the age of 3 is basically unintentional. However, there is a certain amount of time to pay attention to activities that are of interest. For example, a 1.5-year-old child can focus attention on something of interest for 5-8 minutes, a 2-year-old can reach 10-12 minutes, and a 3-year-old can focus for 10-20 minutes. Attention has a special role in the mental development of children, ensuring that they receive clearer and richer information from their surroundings and that the infant will persist in the activity in which he or she is engaged to the end. The formation and development of early attentional qualities are related to the acquisition of early experiences and influence the academic performance of children in later years. The effects of ADHD on learning, life, and social functioning can last a lifetime. Although attention deficit hyperactivity disorder is diagnosed at school age, most of the early manifestations can be seen in infancy and early childhood. Therefore, early attention and timely intervention are needed. Six, pay attention to the development of good habits Habit is a repetitive, usually unconscious routine behavior patterns. A person’s daily activities are basically repeating the original action behavior, and then subconsciously transformed into programmed inertia. These behaviors operate automatically without thinking. The age of 2-8 years is a critical period for habit development and formation, including good habits of life, behavior and study habits. The earliest habits to begin to develop are habits of living, followed by habits of behavior in interpersonal interaction, self-service, and active learning. The habits that need to be developed in early childhood include sleep, eating, bowel movements, and manners. The specific requirements are as follows: (1) In terms of eating, children are required to eat on time. We need to make sure that they eat at the right place, at the right time, and at the right time. (2) In the area of sleep, arrange a reasonable sleep and rest system. Also, we should set the place, quantity and time for sleep. (3) In terms of bowel movements, we should train the habit of defecation and bowel movements at regular times and places. (4) In terms of habitual behavior, we should educate to develop the habit of treating people politely and correcting bad behavior. During the development of infancy and early childhood, since all aspects of development are interrelated and intertwined, attention should be paid not only to the development of motor (gross and fine motor), language, personal interaction behavior, and social adaptation, but also to the early development of attachment, attention, and good habitual behavior, in order to achieve comprehensive and integrated development.