A power plant is provided which is capable of not only achieving the improvement in responsiveness, weight reduction, and manufacturing cost reduction of the power plant, but also enhancing the efficiency of the vehicle. The rotational speeds of first to third rotary elements satisfy a collinear relationship in which the rotational speeds are aligned in a single straight line in a collinear chart in the mentioned order, with the first and second rotary elements being connected to a first rotating electric machine and wheels, respectively, and first and second blocking/connecting members of a first one-way clutch being connected to the first and second rotary elements, respectively. In a case where the first and second rotary elements rotate in a first predetermined rotational direction by transmission of rotational motive power from the first rotating electric machine, transmission of rotational motive power from the first blocking/connecting member to the second blocking/connecting member is blocked. In a case where the second and first rotary elements rotate in the first predetermined rotational direction by transmission of rotational motive power from the wheels, transmission of rotational motive power from the second blocking/connecting member to the first blocking/connecting member is connected. A second one-way clutch allows rotation of the third rotary element in the first predetermined rotational direction, and prevents rotation of the third rotary element in a direction opposite to the first predetermined rotational direction.