An electric parking brake system is equipped with a parking brake driven by an electric actuator for braking wheels of a vehicle, a vehicle condition sensing section for detecting vehicle conditions, a target braking force setting section for setting a target braking force on the basis of vehicle condition detected, compared and weighted by the vehicle condition sensing section so as to overcome a trouble of a part of sensing section, a parking condition detecting section for sensing a change of the vehicle condition from a stopping condition to a parking condition, and a control section for increasing a braking force according to the change in the vehicle condition so as to avoid a creep movement of the vehicle. Thereby, the electric parking brake system with a highly improved reliability can be provided.