To provide a lean type motor tricycle intending enhancement of comfortable ride by stopping unnecessary lean movement of a front body part by reactive driving force of a propeller shaft.

The rotational driving force of an engine 7 is transmitted to a rear wheel 26 through a propeller shaft 37, and a transmitting unit 23 is divided into two parts to form a front unit 27 and a rear unit 28. The front unit 27 is mounted to the front body part F so as to make it vertically rockable, and the rear unit 28 mounted to the front unit 27 so as to make it horizontally movable. The transmitting unit 23 is equipped with a braking device 41 to regulate the lean movement of the front body part, and a sensor to detect a throttle opening is provided in the intake device of an engine 7. Based on an amount of change in the opening of the throttle, the start of increase and decrease of the reactive driving force of propeller shaft 37 is detected by accelerating and reducing a speed. Thereby, the lean movement of the front body part F is regulated by operating the braking device 41.