Abstract: Objective To describe the prevalence of overweight and obesity in preschool and school-aged children in China, and to compare the impacts of different criteria to the evaluation of overweight and obesity.Methods With multiple stage stratified cluster sampling, 1788 children were chosen from 9 urban and rural regions of China and measured for their weight and height between September 2011 and April 2012.The detection rate of overweight and obesity under four criteria was calculated with SPSS 13.0.Results Among the children, the prevalence rate of overweight and obesity were 17.4% and 6.7% according to the criteria of World Health Organization(WHO), 15.0% and 5.7% to that of International Obesity Task Force(IOTF), and 18.5% and 8.1% to Centre for Disease Control and Prevention of United States(US CDC), respectively, with the highest detection rate of overweight and obesity using the criteria of US CDC, the intermediate of WHO, and the lowest of IOTF.Among the children aged 7 years and above, a higher detection rate of obesity in the girls was observed using the criteria of Working Group on Obesity in China (WGOC) than using the criteria of WHO and IOTF, but obvious lower detection rates of overweight in the girls, overweight and obesity in the boys were found using the criteria of WGOC than using the criteria of WHO and IOTF.Conclusion The detection rate of overweight and obesity with the US CDC criteria are higher than those with the IOTF criteria and the detection rate varies with the age when using the WHO criteria among Chinese children of 3 to 11 years old.The results demonstrate a high consistency among the criteria of the three international institutions but a poor consistency between the WGOC criteria and those of the institutions when the criteria are applied among the Chinese children.