Abstract: A door lock with an improved structure is disclosed. It has a turning device that includes a positioning base. The positioning base is mounted with a circular spacer with a lock control device therein. A connecting shaft for driving the lock control device is provided with a limiting element that has a protruded stopping part at its end. The lock has a lock core whose one end allows the insertion and turning of a key. Its other end is connected with the connecting shaft and has grooves, so that the stopping part of the limiting element blocks the lock core when the door is locked.