After birth, children can be divided into seven stages according to age: neonatal, infant, early childhood, preschool, school-age and adolescence. In order to better protect the health of children, the “4.2.1” health care system is implemented, i.e. one check-up every three months within one year of age, one check-up every six months between two and three years of age, and one check-up every year above three years of age. It mainly includes growth and development monitoring, physical examination, routine auxiliary examination and psychological screening for special requirements. The focus of health care at different ages is as follows: (a) Neonatal period (0-28 days) Characteristics: Various functions are relatively naive, the ability to adapt to the environment and resistance to disease are weak, and the reactivity to disease is quite poor, so the mortality rate is high. Neonatal diseases are often related to the “fetal period” and the delivery process, such as premature birth, malformation, asphyxia, neonatal jaundice, neonatal tetanus, umbilical cord disease, respiratory tract infections, diarrhea, etc., all of which are common. Key points of health care: Community neonatal visits are conducted by the community health center twice for comprehensive physical examination, such as weight, length, temperature, head circumference, facial color, skin, etc. To understand the health, feeding, sleep, disease, especially jaundice, etc. Take good care of the newborn’s mouth, umbilical cord, skin and other aspects. Encourage breastfeeding, vaccination and prevention of various common neonatal diseases. Pay attention to eye contact, touch, and listen to more soft music. Recommend newborn screening and monitoring of hearing. (II) Infancy (28 days-1 year) Characteristics: First growth spurt in life, more demand for nutrition, but prone to vomiting, diarrhea, anemia, malnutrition and other diseases due to poor digestive function. After 6 months, certain immune capabilities acquired from the mother gradually disappear, and the child is susceptible to infectious diseases. The cerebral cortex is not yet mature enough to tolerate high fever, toxins or other adverse stimuli, so neurological symptoms such as convulsions easily occur. Health care points: advocate breastfeeding, add complementary foods after 6 months. The diet is sometimes moderate, advocate more sunshine, pay attention to adding vitamin D, pay attention to dietary hygiene. Generally, health care is done every three months, and psychological assessment of temperament and neuropsychological development can be done. Pay attention to early education including various sensory stimulation, grasping training, sitting, standing and walking training, etc. Complete the basic immunization program and prevent various accidents and infectious diseases. (3) Early childhood (1 year old-3 years old) Characteristics: The functions of various systems gradually develop, language, behavior and expression skills are obviously developed, milk teeth gradually come out and fontanelle closes. This stage has a higher incidence of infectious diseases, and is also prone to digestive disorders and nutritional deficiencies. Health care points: general autumn 8 months – 1 year old weaning, more breast milk can be properly delayed weaning time, but do not exceed 2 years old. Generally do health care every six months, psychological aspects can do temperament assessment, neuropsychological development assessment, etc.. Pay attention to early education, life habits training, prevention of various accidents, infectious diseases and digestive system diseases. (D) Preschool period (3 years old-6 or 7 years old) Characteristics: The physical development is growing steadily and the intellectual development is becoming perfect. During this period, children have a strong desire for knowledge and high plasticity, which improves their ability to live independently, learn to take care of themselves and do simple chores. However, they are prone to accidents, and safety education must be strengthened to prevent accidents such as car accidents, trauma, burns, electrocution and drowning. Diseases related to immune response such as nephritis, rheumatism, allergic purpura, etc. are on the rise and still susceptible to infectious diseases. Key points of health care: regular monitoring of growth and development, generally once a year, psychological aspects can be done sensory integration assessment, temperament assessment, neuropsychological development assessment, etc. Pay attention to early education, cultivate good living and hygiene habits, play education, strengthen physical exercise, strengthen the prevention and control of infectious diseases, and prevent accidents. (E) School age (6 or 7 years old-12 years old) Characteristics: Steady physical growth, milk teeth are replaced by permanent teeth in turn, except for the reproductive system, the development of other organs is close to the adult level by the end of this period, and the morphological development of the brain is basically the same as that of adults. Health care points: prevent various common diseases such as myopia, dental caries, intestinal parasites, etc., ensure nutrition, strengthen physical exercise; ensure adequate sleep and rest, regular health checkups, psychological assessment of sensory integration, temperament assessment, ADHD, intelligence and behavior related assessment for those with learning difficulties, etc. We aim at the all-round development of moral, intellectual, physical, aesthetic and labor, and cultivate good psychological quality, living and hygiene habits, moral quality and study habits. Pay attention to parent-child relationship and changes in children’s emotions and behaviors to reduce the incidence of mental behavior disorders. Prevent colds and pay attention to the occurrence of asthma and allergic purpura. (VI) Adolescence (individual differences, girls 11, 12 years old – 17, 18 years old, boys 13, 14 years old – 18, 20 years old) Characteristics: It is the “transition period” from childhood to adulthood, and in recent years there is a tendency to advance. The distinctive feature is that the development of the reproductive system is becoming increasingly mature, during this period girls are menstruating, boys are overflowing with sperm, the second peak of physical growth occurs, weight and height growth increases. Physiological changes, social contact, easy to cause psychological, behavioral and spiritual instability. Prone to menstrual disorders, goiter, psychological disorders or psycho-behavioral disorders, etc. Health care points: prevent various common diseases, ensure nutrition, strengthen physical exercise, ensure sufficient sleep and rest, and carry out annual health care. Pay attention to parent-child relationships and changes in the emotions and behaviors of adolescents, and prevent drug abuse, alcoholism, smoking and other undesirable behaviors and various mental health disorders.