3,344 Children aged between 10 to 16 years from grade 4 to 10 were recruited to explore potential explanatory variables of low self-esteem among rural school-aged children in China. The results showed that the RSE scores were slightly higher for girls than for boys and higher academic achievement didn't contribute higher RSE scores in rural China. A lower height Z-scores resulted in a lower self-esteem in girls, and low SE was associated with height Z-score less than -1 versus scores more than -1 (OR=1.69, 95% CI 1.19-2.38, P=0.003). The findings indicated that it was height and BMI rather than weight to girls and weight to boys that were significantly associated with low self-esteem in rural China under the premise of very low rate of obesity.Self-esteem, also called self-worth, is a major predictor of satisfaction with life. A number of studies have investigated the factors that affect self-esteem on children, and current research focus such as the impacts of gender, [1] socio-economic status, [2] academic achievement, [3] age, [4] weight [5,6] and BMI [7] on self-esteem often reached conflicting conclusions in different areas or in different population. A theory of social comparisons explains how individuals evaluate their own opinions and abilities by comparing themselves to others who are similar to the self or who are upward (superior to the self) or downward (inferior to the self) on some attributes or di-