Abstract: A power transmission and pedal force sensing system for an electric motor includes an electric motor, a gear reduction train, a pedal force sensing system, and a power combination mechanism. These four mechanisms are concentrically, closely mounted in a single casing. The pedal force sensing system includes a pedal force transmitting sleeve having an elastic device mounted therein, and a pedal force sensing sleeve mounted outside the pedal force transmission path for converting the pedal force into an axial displacement. A proximity sensor is used to detect the axial displacement and outputs a voltage signal representing the magnitude of the pedal force. The power transmission path is shortened and only one casing is required to house all of the elements to thereby obtain a structure of a higher transmission efficiency and reduced volume and weight.