The invention provides a swing-type power unit integrally including an engine and a transmission, characterized by facilitating works of assembling accessories in the engine. To achieve this, a swing-type power unit P integrally includes an engine E and a belt-type continuously variable transmission T for transmitting a drive force of the engine E to a drive wheel Wr and is swingably supported on a body frame. The engine E is separable from the transmission T along a parting plane P 6 , and a radiator 49 and a cooling water pump 53 as accessories for cooling the engine E are concentratedly disposed on the engine E side. As a result, the radiator 49 and the cooling water pump 53 can be easily assembled in the engine E from which the transmission T is separated in a state in which the engine E is stabilized with the parting plane P 6 directed downwardly.