A preceding vehicle following cruise control is configured to shift automatically from a low speed following cruise control mode to a high speed following cruise control mode when a vehicle speed changes from a low speed region to a high speed region while a vehicle speed setting is set. Alternatively, the preceding vehicle following cruise control system is configured to shift automatically from the low speed following cruise control mode to the high speed following cruise control mode when the vehicle speed changes from the low speed region to the high speed region while a history of mode switching operation history indicating that the following cruise control mode has been changed from the low speed following cruise control mode to the high speed following cruise control mode is stored in a memory section.