This door lock adopts ratchet-pawl structure, and consists of front door lock, rear door lock, internal and external maneuver structures. Due to the plastic-bound technique on ratchet and pawl, it's convenient to open and close the lock, without noise when intermeshing. Rotate anticlockwise 60 degree or push down inner security button, you can close the door. Contrariwise, you can open the door. The front door has the mis-lock avoiding function. This lock mainly mates to light trunks of Nanjing Automobile company and 2ND Automobile company, also fits for such medium class or high class cars as saloons coaches.