Introduction: Factors such as social and economic conditions, technological development, modern urbanization, lifestyle, physical activity, nutrition, and air pollution affect physical growth and development. Aim: To study the physical development of Mongolian children. Objectives: 1. To measure the physical indices (weight, height) of children aged 6-17 years old with some influencing factors. Material and method: Using a random sampling method, children's body height and weight were examined at a particular point in time using widely accepted methods. Statistical analysis was performed using the "SPSS ver.25" program. Result: The growth of children's height and weight is progressing according to general patterns of age and gender. Girls grow rapidly between the ages of 10-13 and stabilize after wards, while boys a sharp growth spurt between the ages of 13-17, with the average height of 17-year-old boys being 171.44 cm and 160.25 cm for girls, which is slightly higher than previous studies (Otgon G, 2006, Munkhzaya M, 2020). The trend of weight growth is more prominent in boys. However, compared to international standards (Russia, WHO, CDC), our children's height and weight are lower. The statistics show that parental education, income, exercise, and living environment positively influence growth and development, whereas excessive television watching and air pollution negatively affect it (p< 0.05). Conclusion 1. Children's growth is normal, but observed increase of the body weight of boys. Having healthy and well educated parents, as well as engaging in physical activity positively influences children's height. A lack of physical activity negatively affects height and increases weight. Mongolian children are shorter and lighter compared to foreign children (from Russia and America - CDC).