Abstract: Objective To learn the situation and main relative risk factors of overweight and obesity in Chongqing.Methods The population aged above 18 years old was sampled by randomized cluster sampling.Background information was collected by face-to-face interview.Data on weight and height was obtained through physical check-ups.The relative risk factors were screened by Logistic regression analysis.Results There were 4183 subjects were interviewed and physically measured.The prevalence rates of overweight and obesity were 27.0% and 8.2%.Both the rate of overweight and the rate of obesity in cities and females were all higher than that in rural areas and males.The results of Logistic regression analysis showed that major risk factors influencing overweight and obesity were residence,sex,age,household income and physical activity.Conclusion Many citizens in Chongqing were considered to be overweight and obesity,which became an important public health problem.Integrated measures must be taken for prevention and control.