A charging system provided for vehicles prevents theft of a charging cable, insertion of foreign matter into a vehicle-side receptacle, or tampering when an onboard battery usable for running power is charged from a household power supply. A cable connector of the charging cable is opposed to the vehicle-side receptacle in a connecting part to prepare for charging. When a PHV is exited, a switching command switching from an unlocked state of a door locking mechanism to a locked state is inputted to a PHV ECU responsive to an inputting manipulation performed on a key or door key sensor. The PHV ECU allows the door locking mechanism to switch from the unlocked state to the locked state. The PHV ECU allows locking mechanisms to switch from the unlocked states to the locked states in the manner interlocked with the switching action of the door locking mechanism.