Abstract: The purpose of this study was to determine the effects of parental support and physical activity (PA) level of parents on the moderate-to-vigorous physical activity (MVPA) of their children, based on the survey of children and their parents in Shanghai.The gender difference was also examined.Parental support was composed of two dimensions such as logistic support and explicit modeling.The findings of this study indicated that the average MVPA time of Children was 19mins/day.Furthermore, boys were physically active than girls but no significant differences in logistic support of parents between boys and girls were detected.Regression results indicated that the variance of MVPA of boys was explained by fathers' explicit modeling and PA participation, while the variance of MVPA of girls was explained by mothers' explicit modeling.It is concluded that parental support and PA level significantly influenced MVPA time of their son or daughters.Furthermore, parental influence on their sons was higher than that on their daughters.The parental influence was characterized by the same-sex effect.