A vehicle control system comprising: a vehicle-mounted device mounted on a vehicle; and a mobile device that is portable by a user, wherein the vehicle-mounted device permits a predetermined operation on the vehicle based on a response signal which is transmitted from the mobile device in response to a request signal transmitted from the vehicle-mounted device, the vehicle-mounted device includes a first communication device (33, 12) or the vehicle control system comprises a portable object of the user, which includes the first communication device (33, 12), wherein that first communication device (33, 12) performs a wireless communication with the mobile device under a predetermined communication protocol, and the mobile device includes: a second communication device that performs the wireless communication with the first communication device (33, 12) under the predetermined communication protocol; and a control unit that responds to the request signal under a condition that the mobile device is located in a communication range of the first communication device (33, 12) and the wireless communication between the first communication device (33, 12) and the second communication device is established under the predetermined communication protocol, wherein the control unit does not respond to the request signal when the mobile device is located outside of the communication range of the first communication device (33, 12) and the wireless communication between the first communication device (33, 12) and the second communication device is not established under the predetermined communication protocol, characterized in that the predetermined communication protocol is different from a communication protocol of the request signal and a communication protocol of the response signal. a vehicle-mounted device mounted on a vehicle; and a mobile device that is portable by a user, wherein the vehicle-mounted device permits a predetermined operation on the vehicle based on a response signal which is transmitted from the mobile device in response to a request signal transmitted from the vehicle-mounted device, the vehicle-mounted device includes a first communication device (33, 12) or the vehicle control system comprises a portable object of the user, which includes the first communication device (33, 12), wherein that first communication device (33, 12) performs a wireless communication with the mobile device under a predetermined communication protocol, and the mobile device includes: a second communication device that performs the wireless communication with the first communication device (33, 12) under the predetermined communication protocol; and a control unit that responds to the request signal under a condition that the mobile device is located in a communication range of the first communication device (33, 12) and the wireless communication between the first communication device (33, 12) and the second communication device is established under the predetermined communication protocol, wherein the control unit does not respond to the request signal when the mobile device is located outside of the communication range of the first communication device (33, 12) and the wireless communication between the first communication device (33, 12) and the second communication device is not established under the predetermined communication protocol, characterized in that a second communication device that performs the wireless communication with the first communication device (33, 12) under the predetermined communication protocol; and a control unit that responds to the request signal under a condition that the mobile device is located in a communication range of the first communication device (33, 12) and the wireless communication between the first communication device (33, 12) and the second communication device is established under the predetermined communication protocol, wherein the control unit does not respond to the request signal when the mobile device is located outside of the communication range of the first communication device (33, 12) and the wireless communication between the first communication device (33, 12) and the second communication device is not established under the predetermined communication protocol, characterized in that the predetermined communication protocol is different from a communication protocol of the request signal and a communication protocol of the response signal.