Objective: To explore characteristics of dynamic and static balance of children aged 8 to 10 years, and to provide a reference for prevention of injuries caused by physical activities among obese children and the choice of facilities for physical activities. Methods: Totally 100 obese children and 100 normal children were selected as the subjects by one legged jumps from 5 primary schools in economic and technological development district of Hefei, the proportion of male and female children was 1∶1 in each group. IIM-BAL-100 balance tester was used to assess the static balance ability under double feet standing with eyes closed and right foot standing with eyes opened. The dynamic balance of double feet standing with eyes opened was measured by the Balance check dynamic balance tester. Two factor analysis of variance (ANOVA) was used to examine the effect of obesity and gender on the dynamic and the static balance. Results: In the static balance ability, when standing with both eyes closed, there was no significant difference in all static balance values between groups, genders and the interaction between the two factors( F=2.33, 0.42 ,0.76, P >0.05). When standing on one foot with eyes opened, there was significant difference in the static equilibrium index between the groups and the gender( F=2.72, 3.07, P <0.05). In terms of dynamic balance ability, all the dynamic balance indexes had statistically significant differences among the groups( F=43.67, P <0.01). Conclusion Obesity can significantly reduce the ability of single leg static balance and dynamic balance in 8-10 year old children. Sex can significantly affect the single foot static balance ability of 8-10 year old children, but it has little effect on the dynamic balance ability of 8-10 year old children.