This study aimed to examine the association among parental moderate-to-vigorous physical activity (MVPA), parental support, and the MVPA of children by gender. Participants comprised of 172 boys and 151 girls aged seven to 11 years old from three primary schools in Shanghai. Their parents were also included as research respondents. Accelerometers were utilized to measure MVPA duration among the children. Questionnaires that focused on parental support and MVPA were completed by the parents. Results indicated that only 4% of the children met the recommended MVPA duration of 60 minutes per day based on objective data. Parental support consisted of two constructs: logistic support and explicit modelling. Boys engaged in more MVPA than girls although no gender differences were noted in terms of the logistic support and explicit modelling of parents and their MVPA. A regression analysis revealed that 23.3% of the variance in MVPA for boys was explained by explicit modelling and MVPA of fathers. Moreover, 10.5% of the variance for girls was explained by the explicit modelling of mothers. Thus, parents should be highly encouraged to support the MVPA of their children by acting as role models. They can also enhance the MVPA of their children using different methods based on gender.