Objective To analyze the effect of family factors relating to the obesity of pre-school children,so as to figure out the epidemiology evidence and available intervention on the children obesity. Methods As to quantitative research,the obesity children of a series of communities in Minhang district were selected relied on the randomized cluster sampling method,meanwhile the non-obesity children were paired simultaneously. Results Girl taking more physical activity relied on the attitude of parents,having more food required by parents were the protective factors of obesity and overweight of children,but family history of overweight and obesity,overtaken food,longtime sleep,the attitude of obesity no harm were the risk factors of obesity and overweight. Conclusion Of prime importance is the recognition that the attitude of parents is the risk factors,so as to available intervention of children obesity based on family will be effective.