A self-propelled platform for a small watercraft. The platform is used to carry a small watercraft from a storage place on the land to sea, and when the watercraft is in use, the platform enables the watercraft to be moored and stored on sea. The platform also enables preparation work for the use of the watercraft to be performed easily and safely by only one person. The platform has a body portion (2) for removably receives a watercraft body, wheel portions (4a, 4b) arranged below the body portion (2), power portions (5a, 5b) for driving the wheel portions (4a, 4b), power transmission portions (6a, 6b) for connecting the power portions (5a, 5b) and the wheel portions (4a, 4b), a control portion (11) for controlling the drive of the wheel portions (4a, 4b), and floating body portions (7a, 7b) installed to the body portion (2).