A LED lamp for easy assembly and fixation includes a fixing plate, a vapor chamber, a LED module, an outer frame, and fixing elements. The fixing plate has assembling holes. The vapor chamber has a heat-releasing surface brought into thermal contact with the fixing plate and a heat-absorbing surface opposite to the heat-releasing surface. The LED module includes a circuit board and LEDs arranged on the circuit board. The outer frame is provided with through-holes corresponding to the assembling holes and an accommodating opening corresponding to the LEDs. The fixing elements penetrate the through-holes and the assembling holes respectively to assemble the outer frame with the fixing plate. With this arrangement, the vapor chamber and the LED module can be sandwiched between the outer frame and the fixing plate. Thus, the present invention can be assembled and fixed to a predetermined position with an excellent structural strength.