Why do people have tall and short bodies? The body belongs to the hereditary traits, genetic factors play a big role in height, but it is not absolute. Height is affected by many factors: 1, genetic: pediatric growth and development characteristics, potential, tendency, etc. are affected by both parents’ genetic factors, that is, the race and the family’s far-reaching genetic information. 2, gender: boys and girls have their own rules and characteristics of growth and development, so in the evaluation of pediatric growth and development, respectively, according to male and female standards. Xiang Rong, Department of Pediatrics, Nankai Hospital, Tianjin, China 3, Nutrition: Children’s growth and development must have a perfect supply of nutrients, adequate and reasonably deployed nutrients, can make the growth potential to get the best performance. 4, disease: disease on the growth and development of the interference effect is very obvious, acute infections often make weight loss; long-term chronic disease affects the weight and height of the development; endocrine diseases often cause bone growth and delayed development of the nervous system; congenital diseases on the growth and development of the impact is more obvious. 5.Mother pregnancy: the development of the fetus in the uterus is affected by various factors such as the living environment, nutrition, emotion and disease of the pregnant mother. Living environment: Living environment plays an important role in children’s health. A good living environment (including sufficient sunlight, fresh air, water, cleanliness, no noise, spaciousness, etc.), healthy living habits and scientific care, correct upbringing and physical exercise, and sound medical care services are all important factors in ensuring that children’s growth and development are at their best.