Abstract: An automatic sliding door system for vehicles to operate opening and closing movements of a sliding door of a vehicle automatically and safely from a driver's seat as well as outside of the vehicle, comprises a guide rail affixed to the body so that the sliding door can be guided along the rail by sending wires firmly connected to the door by an electric motor, an operating device consisting of two parts, one being mounted near the driver's seat and another being mounted inside the body adjacent to the sliding door, a door lock releasing device mechanically or electrically connecting a door lock of the sliding door at one end and the operating device at another end through a coupling which is joint when the door is closed but separated when the door is opened, and a control device connected to the operating device to control movements of the sliding door in accordance with operation of the operating device.