Objective To describe the prevalence and relationship between physical activity (PA),depressive symptoms and school life satisfaction among middle school students in Bengbu,Anhui province.Methods A total number of 5268 boys and girls were analyzed from 4 middle schools.Depressive symptoms were assessed,using the Depression Self-rating Scale for Children,school life satisfaction via the School Life Satisfaction Rating Questionnaire.Self-reported PA and sedentary behaviors were also assessed.Descriptive statistics and logistic regression models were used.Results Adolescents self-reported rates of participating in sufficient moderate,vigorous and insufficient PA were 14.7％,36.0％ and 59.1％,respectively.The prevalence rates on depressive symptoms and school life dissatisfaction were 24.4％ and 25.9％.After adjusting on sedentary behaviors and other potential confounders,participants who had engaged in sufficient moderate and vigorous PA had odds ratios of 0.73 (0.60-0.89),0.68 (0.59-0.79) and 0.76 (0.63-0.92),0.70 (0.61-0.81) for likelihood of being depressive and school life dissatisfaction,compared to their counterparts who participating in insufficient moderate and vigorous PA.Insufficient PA was positively associated with depression and dissatisfaction of their school lives [OR (95％ CI):1.42(1.24-1.63) and 1.45 (1.27-1.66)].Conclusion High prevalence of insufficient PA was seen among adolescents and PA was closely related to the presence of depressive symptoms and school life dissatisfaction among middles school students.