A motor direct driven compressor system includes a motor, a coupling and a compressor, and the coupling is coupled between the motor and the compressor, and a second assembling portion, a coupling portion and a metal plate of the coupling are used for connecting a driving shaft of the motor and a transmission shaft of the compressor. With this design, the driving force of the motor can be transmitted to the compressor and provided for the operation of the compressor. In addition, errors produced by the rotation and transmission during the transmission process can be minimized, so that the compressor can be operated accurately and normally.