Objective  To understand the current situation and characteristics of body composition of Inner Mongolia Chahar tribe.    Methods  The body composition of 403 adults (161 males and 242 females) in Chahar of Inner Mongolia was measured by bioelectrical impedance analysis.    Results  The body muscle mass of male and female was the largest, the lower limb muscle mass was medium, and the upper limb muscle mass was the smallest.The results of variance analysis showed that there were statistically significant differences in height, body fat rate, estimated bone mass, visceral fat grade, muscle mass of left and right upper limbs, trunk fat rate and muscle mass among men.The results of correlation analysis showed that the body fat rate increased with age, while the body fat rate, height, estimated bone mass, visceral fat grade, left and right upper limb muscle mass and trunk muscle mass decreased with age.Except for water rate and muscle mass of left and right upper limbs, there were significant differences in other 15 indexes among age groups.The results of correlation analysis showed that trunk fat rate and visceral fat grade increased with age, while height, total muscle mass, estimated bone mass and trunk muscle mass decreased with age.The results of u test showed that except body mass index(BMI), there were statistically significant differences in 17 body composition values between genders in Inner Mongolia Chahar.The total fat percentage and BMI of Inner Mongolia Chahar are in the middle among the seven Mongolian ethnic groups.According to the results of principal component analysis of 11 ethnic groups, the fat content of men and women in Inner Mongolia was higher, and the muscle content was medium.    Conclusion  The body fat development level of Inner Mongolia Chahar was slightly lower than that of northern Western Mongolian, and slightly higher than that of Eastern Mongolian; the overall development level of body composition is close to that of northern Mongolian, but higher than that of Southern Mongolian.