Objective To discuss the law of the change of body composition of Zhuang-Dong ethnic groups with the change of natural geographical factors(longitude, latitude, annual average temperature and annual average sunshine).    Methods  The bioelectrical impedance analysis (BIA) was used to measure the body composition data of 5098 cases of 13 ethnic groups of ZhuangDong group in China. At the same time, collect the relevant data of longitude, latitude, annual average temperature and annual average sunshine of 13 ethnic groups, and use per capita disposable income as a control variable to perform partial correlation analysis about body composition with longitude, latitude, annual average temperature, and annual average illumination.    Results  Zhuang-Dong group fat rate decreased and little change in muscle mass, presumption of bone mass, and water content with the increase of longitude. With the increase of latitude, the fat rate of males in the Zhuang-Dong ethnic group decreasesd, muscle mass increased (mainly muscles in the extremities), female fat rate increased, and muscle mass decreased (mainly in upper limbs and trunk muscles).In general, with the increase of the average annual temperature, the fat rate of males in Zhuang and Dong ethnic groups increased, lower limb muscles decreased, female fat rate decreased, and muscle mass increased. With the increase of the average annual sunshine, the body fat rate of men increased and the muscle mass decreased; the body fat rate of women decreased and the muscle mass increased.    Conclusion  Natural geographical factors (longitude, latitude, annual average temperature, and average annual sunshine) have significant effects on the body composition of the Zhuang-Dong ethnic group.