The cargo transport system according to this invention employs a tow vehicle that can automatically follow and run upon guide lines. The tow vehicle can tow cargo laden equipment such as container dollies to thereby automatically transport the air cargo. The air cargo is conveyed by an underground air cargo conveyor mechanism which has the conveyor line including the guide line installed underground to link the air cargo holding area in the airport terminal building and the aircraft parking area. Further, the system connects the loading/unloading cargo door of the aircraft and the underground loading/unloading position for the underground air cargo conveyor mechanism by an air cargo elevator.