Abstract: Attention deficit and hyperactivity are the main clinical manifestations of children with ADHD. The behavioral characteristics of their hyperactive symptoms are: hyperactivity without a clear purpose; hyperactivity is difficult to self-control. The hyperactive symptoms are not constrained and limited by the environment and behavioral norms, and the behavior is impulsive and capricious and the symptoms are repetitive; the performance of hyperactive behavior varies among age groups. Familiarity with the behavioral characteristics of ADHD can help in the differential diagnosis of the disease. Understanding the time of onset, developmental trends and prognosis of ADHD symptoms can help to provide timely behavioral intervention and treatment for children with ADHD. Inattention and hyperactivity are the main clinical manifestations of Attention dificit hyperactivity disorder (ADHD), and the diagnosis of ADHD is currently defined by behavioral characteristics and based on standardized scales. The behavioral characteristics of attention deficit symptoms in children with ADHD have been described in a separate article. The behavioral characteristics of ADHD children with hyperactivity symptoms have the following behavioral characteristics. ADHD children with ADHD have the following behavioral characteristics. 1. no clear purpose Motivation is the internal motivation that directly drives a person’s behavioral activities. It motivates the individual to produce a certain behavior, and makes the individual’s behavior directed to a certain goal. It regulates the degree, timing, and direction of the individual’s behavior. The activities of normal children and the ADHD symptoms of naughty children are mostly motivated by the desire to achieve a certain goal. Thus, their behavior is systematic and has a beginning and an end. For example, they return stationery borrowed from the next student in class in a timely manner and whisper “thank you”. They often answer the teacher’s questions without raising their hands in order to demonstrate their ability. Can do well from the beginning to the end of a task that interests him/her. Children with ADHD may watch TV without saying a word or allowing others to chatter. In contrast, ADHD children have no clear motivational purpose for their ADHD symptoms. As a result, the direction of the behavior is not clear, and the intensity and duration of the behavior are weak and short. Therefore, the hyperactive symptoms appear to be fragmented, disorganized, with no end in sight, and constantly changing patterns. For example, in class, he or she may use a pencil and penknife to draw on textbooks or desks, or play with stationery or bite nails. …… At home, it is difficult to have a quiet time, watching TV while playing, running around on his knees, dancing, busy, making the surrounding people unbearable ……. Parents say, “My child can’t do anything to play”. But the hyperactivity of children with ADHD is not always a result of increased activity compared to normal children. Some foreign scholars have used video cameras to record the activities of a group of ADHD and normal children over a long period of time, including playgrounds, classrooms, dining halls, games, and walking. It was found that children with ADHD were not more active than normal children. It is only because ADHD children’s activities have no clear purpose, do not distinguish between time and occasion, and frequently change the content of activities, thus giving people the impression of “hyperactivity”. 2, ADHD symptoms are difficult to self-control People are not only the masters of objective reality, but also the masters of themselves. ADHD children’s poor self-control ability is manifested in the following aspects. 2.1, hyperactivity symptoms are not subject to the constraints and limitations of the environment and behavioral norms The activities of normal children and the hyperactivity of naughty children can be self-restrained and controlled under certain environmental conditions. For example, they can be quiet and disciplined when an outside teacher observes and listens to the class. They can wait in order when participating in play activities. In contrast, children with ADHD have difficulty keeping quiet even when they are told the rules to follow or are placed in special seats to listen to the lesson, and will keep wriggling and making small movements. Participate in game activities either out of order to jump the queue or abandoned to do ……. Therefore, their hyperactivity symptoms will be indiscriminately and uncontrollably manifested. 2.2, hyperactive behavior impulsive capricious A person from the decision of its behavioral actions to the implementation of the implementation of the activity has a certain time gap. As a person grows older, this “behavioral decision-making ability” should become increasingly mature and stable. Children with ADHD have a short time lag between the decision to act and the implementation of the behavior, and lack the patience and self-protection appropriate to their age. They do not have the ability to “think things through”. As a result, their behavior is often reckless, dangerous, destructive, and prone to accidents. Such as obstinate, capricious, impulsive and reckless. At home, they rummage through boxes and cupboards without purpose, and lose toys and stationery at will, without caring for them. Interrupt first when talking to others or answering questions from teachers. They are troublemakers at school and in public places and like to climb high and over railings. Suddenly crosses the road in front of a moving car. They do not know how to swim but go into the water at will, etc. On the contrary, they do not adapt quickly to a new environment and have poor tolerance. Weak will, impatience, lack of confidence and avoidance when encountering difficulties. 2.3. The repetitive nature of hyperactivity ADHD children have difficulty controlling their hyperactive behavior because of the dopamine neurotransmitter deficiency, resulting in dysregulation of their excitatory and inhibitory functions. Although their hyperactivity symptoms can be recognized and corrected by teachers’ and parents’ patient education and criticism, they will still be the same and relapse due to poor self-control. This results in repeated offenses. In contrast, the hyperactivity of naughty children will be criticized and punished after a significant improvement, or will be repeated only after a considerable period of time. 3, the behavioral characteristics of hyperactivity symptoms at each age ADHD children’s hyperactivity symptoms can be manifested in infancy and preschool age. The most pronounced manifestations are found in the elementary school age. It can continue into adolescence and even adulthood. ADHD symptoms have different behavioral characteristics at each age. 3.1, Infancy and Preschool Approximately 30% of children with ADHD have ADHD symptoms in infancy and early childhood, and infants mainly show difficulty in developing regular habits. Mothers will recall significant fetal movement in the child’s womb. After birth, the child is restless in the crib or in the car, irritable, crying, dancing, excited and sleepless, and has difficulty developing regular eating, sleeping and bowel habits. Parents often say, “My child is so difficult to bring up. After walking, the child’s activity is significantly more than that of children of the same age. They run around, climb up and down, make a lot of noise and mess, and are prone to falls and collision injuries, regardless of the occasion. They do not concentrate on their play, they do not have a long heart, and they play with the same toys for a while and then change to another one. After entering kindergarten, they are undisciplined and move around like a motor, do not listen to greetings and do not obey management. They have difficulty listening to the teacher’s explanation and singing, are reluctant to learn, act impulsively and capriciously, and often argue with peers. At this stage, attention should be paid to behavior modification of ADHD symptoms. However, the diagnosis of ADHD must be made in school-age children. 3.2. School age After going to school, ADHD symptoms get more attention from teachers and parents because they have a greater impact on classroom discipline and learning. It is also prominent in school-aged children with ADHD. However, after going to school, they are subject to environmental and behavioral norms, and their hyperactivity symptoms gradually change from widespread purposeless hyperactivity in infancy and early childhood to small movements in class as a prominent manifestation. They cannot control themselves in the classroom seat to twist their bodies, stretch their legs and feet, make small movements or make funny faces to make their classmates laugh …… Children in the lower elementary school may still have a wide range of excessive activities. For example, they may suddenly interrupt the teacher’s lecture, or even knock on the table, whistle, or leave their seats to walk around the classroom. They may also rush out of the classroom during and after school to laugh and play with classmates and cause trouble. However, this widespread hyperactivity in children with ADHD gradually decreases in the upper elementary and middle school years, with attention deficit symptoms accompanied by hyperactivity symptoms becoming the main symptom, and is the main cause of decreased academic performance and learning difficulties. 3.3. Adolescence Only 1/3 of children with ADHD enter adolescence or adulthood when their behavioral symptoms disappear. If school-age children with ADHD do not receive timely and effective treatment, their symptoms can continue into adolescence and adulthood. However, due to increased self-control, ADHD symptoms will gradually decrease or disappear. In contrast, attention deficits and secondary psychobehavioral disorders can still exist to varying degrees. Follow-up data show that most children with ADHD have lower levels of literacy in adulthood than healthy children. About 16.6% of children with ADHD continue to have personality changes such as irresponsibility, difficulty getting along with others, and lack of self-confidence into adulthood. About 11.1% of adults with ADHD as children have mood disorders such as agitation, arrogance, and low self-esteem. The incidence of social interaction problems, lying, truancy, negligent behavior, or juvenile delinquency is also higher than in the normal child group. But the high energy and active personality traits of ADHD children also have their advantages in job searching. Such as being suitable for careers in sales, stock operations, literature, sports, etc. Familiarity with the behavioral characteristics of ADHD children with hyperactivity can help in the differential diagnosis of the disorder. Understanding the time of onset, developmental trends and prognosis of hyperactive behaviors can help to provide timely behavioral interventions and treatment for children with ADHD.