The present invention relates to a connecting assembly for a high mounted stop lamp. The high mounted stop lamp according to an embodiment of the present invention employs a clamping clip and a guide clip so that it can readily attach to the stop lamp without using tools such as a screw driver or a spanner. In particular, the clamping clip of the present invention is provided with a clamping means that firmly fix the high mounted stop lamp to a package tray by spring force. Further, the guide clip employs a simple insert-locking system.