OBJECTIVE To understand the status and related factors of overweight and obesity in children and adolescents aged 6-17 in Yunnan Province. METHODS From 2016 to 2017, 3463 children and adolescents aged 6-17 from 65 primary and secondary schools in 13 counties of Yunnan Province were selected by stratified cluster sampling method for face-to-face questionnaire survey, including 1716 boys and 1747 girls, 2098 elementary school students, 762 middle school students, 603 high school students, of which, 1368 students from urban area and 2095 students from rural area. The questionnaire included information including, weekly consumption of sugary drinks, sweets, puffed food, fruits, vegetables, breakfast, daily activities of moderate or high intensity, school sports, daily hours of playing video games and watching TV, daily sleep and outdoor activities. Height and weight were measured using standard method. SPSS20.0 was used for χ~(2 )test and multivariate Logistic regression analysis. RESULTS The prevalence of overweight and obesity among children and adolescents aged 6-17 were 8.43%(292/3463) and 6.01%(208/3463) respectively. The overweight rates of male students and female students were 8.45%(145/1716) and 8.41%(147/1747) respectively, and the statistic was significant differently(χ~(2 )=0.001, P>0.05). The overweight rates of urban and rural children and adolescents were 11.99%(164/1368) and 6.11%(128/2095) respectively, and the statistic was significant differently(χ~2=37.04, P<0.01). The overweight rates of primary school, middle school and high school were 7.53%(158/2098), 9.32%(71/762) and 10.45%(63/603) respectively, and the statistic was significant differently(χ~2=6.15, P<0.05). The obesity rates of male and female students were 7.11%(122/1716) and 4.92%(86/1747) respectively, and the statistic was significant differently(χ~2=7.33, P<0.01). The obesity rates of urban and rural children and adolescents were 9.50%(130/1368) and 3.72%(78/2095) respectively, and the statistic was significant differently(χ~2=48.97, P<0.01). The obesity rates of primary school, middle school and high school were 7.67%(161/2098), 3.15%(24/762) and 3.81%(23/603), respectively, and the statistic was significant differently(χ~2=26.48, P<0.01). Multivariate Logistic regression analysis showed that cities(OR=2.025, 95%CI 1.646-2.492) and non-residential schools(OR=1.808, 95%CI 1.470-2.223) were associated with overweight and obesity in children and adolescents, both of which were statistically significant(P<0.05). CONCLUSIONS The prevalence of overweight and obesity among children and adolescents aged 6-17 in Yunnan Province were high. Urban, non-residential school children and adolescents are more likely to be overweight and obesity.