Disclosed in the present invention is a dual-structured power output apparatus of an electric drive and power system that provides a means for outputting both mechanical power and electrical power. It comprises dual motor/generators having two stator assemblies, two rotor assemblies and a power transmission unit all integrated into a single housing for easy mounting. The power transmission unit is disposed adjacent to the two motor/generators and coupled on both ends to rotating shafts mechanically linked to the rotor assemblies such that they are rotatable relative to each other. It function is to change the rotational speed and torque of at least one of the rotors in order to reduce weight and physical size of the apparatus, and thus significantly improving the power density and capability. The structure of the apparatus is well-suited to improve the performance and fuel efficiency of the prior art hybrid powertrain.