Abstract: A door lock system including a control mechanism transversely mounted in a door in the middle, a transmission mechanism mounted in one hollow stile at one lateral side of the door and coupled to one end of the control mechanism at right angles, a top latch assembly and a bottom latch assembly respectively fastened to the hollow stile at difference elevations and driven by the control mechanism through the transmission mechanism to secure to the door to a doorframe, the top latch assembly including a shell fixed to the hollow stile on the inside, a frame mounted inside the shell, a latch bolt pivoted to the shell, a push member pivoted to the frame and driven to move the latch bolt, an adjustment device driven by the transmission mechanism to move the push member, and a locating device mounted in the frame and controlled by a fine adjustment device to secure the actuating device to the frame.