Abstract: Objective To examine the prevalence and influencing factors of overweight/obesity among urban school children in China.Methods A questionnaire survey and physical measurement were conducted among 3 986 children selected with multistage random cluster sampling from elementary schools in five cities (Shijiazhuang,Shanghai,Shenzhen,Lanzhou,and Wuhan) across China during December 2013 to June 2014.Results The overall prevalence of overweight and obesity were 19.8% and the prevalcence of overweight and obesity was 10.6% and 9.2%.There were significant differences in the prevalence of overweight/obesity among the school children in diferent cities,at various ages,and between the school boys and girls (P<0.05 for all).The prevalence of obesity in school boys was significantly higher than that in school girls (22.8% vs.16.5%,P<0.01).After adjusting for city and age,logistic regression analysis revealed that physical inactivity (odds ratioOR=4.179,95% confidence interval95%CI:3.492-5.002),male gender (OR=1.218,95%CI:1.019-1.456),without snacking habit (OR=1.346,95%CI:1.047-1.731) were risks of overweight/obesity; while taking meals not fast or slowly (OR=0.532,95%CI:0.335-0.845),taking meals slowly(OR=0.352,95%CI:0.211-0.586),not liking to have meat products(OR=0.723,95%CI:0.549-0.952),and with balanced dietary patterns (OR=0.556,95%CI:0.324-0.965)were protective factors for overweight/obesity among the school children.Conclusion Healthy dietary behaviors and being physically active are focal points when making intervention strategies for the prevention of overweight/obesity among urban school children.