PURPOSE: To provide a universal self-propelled vehicle requiring little steering force and capable of being simply controlled by providing a driving wheel rotated forward, backward, or in the right or left direction against a vehicle body, and changing the grounding point of the driving wheel against the vehicle body with a ground point adjusting mechanism.

CONSTITUTION: When a driver's seat 14 is lowered downward and a cylinder 56 is lowered, the other end 74b of the second link bar 74 is lowered to press a vertical rod 76 down. An arm 78, a holder 84, and a rotary disk 18 are rocked, and a driving wheel 19 is rocked. When the driver's' seat 14 is rotated around the vertical axis, a rotary base 62, a tube 64, a pin support arm 66, the first link bar 72, the second link bar 74, the vertical rod 76, the arm 78, and the holder 84 are integrally rotated around the axis. The rocking face by a link 16 is rotated against a vehicle body 12. The rotary disk 18 is rotated by a motor 20 via a sprocket 24 and a chain 26, and the driving wheel 19 is rotated. A grounding point adjusting mechanism is thus constituted, and the grounding point can be optionally changed with a simple mechanism.