A motion sensitive lamp with a coupling mechanism is provided. The motion sensitive lamp is installed on a wall or a ceiling. The motion sensitive lamp at least includes a lamp body, a base and a coupling mechanism. A coupling mechanism includes an engaging structure, a positioning structure and a limiting element. One of the engaging structure and the positioning structure is installed on the lamp body. The other of the engaging structure and the positioning structure is installed on the base. The engaging structure is inserted into the positioning structure, so that the lamp body is locked on or coupled with the base. When an external force is applied to the limiting element, the external force results in a displacement of the limiting element, so that the limiting element is inserted into one of the base and the lamp body.