To provide a method for transferring a heavy cargo in a barge which can suppress the inclination of the barge with a simple structure.

A heavy truck 10 movable in the horizontal direction is arranged on a deck 14 of the barge 13 connected to a pier 11 via an elevating/lowering ramp member 12, the heavy truck 10 on the deck 14 is moved in accordance with the movement when a self-advancing heavy cargo carrying truck 23 with a heavy cargo 16 loaded thereon is transferred between the barge 13 and the pier 11, and the heavy cargo 16 is transferred by controlling the inclination of the barge 13.