An LED lamp includes a heatsink housing (2) and an alternating current LED module (1). The alternating current LED module includes a heat conducting portion (10) combined with the heatsink housing and two electrical connections (11) electrically connected with an external power supply. Thus, the heatsink housing forms a porous structure to provide a greater heatsink effect and to quickly carry away the heat produced by the alternating current LED module to enhance the heat dissipation efficiency of the alternating current LED module. In addition, the heatsink housing is directly formed to have the profile of a common lamp housing and is provided with a metallic screw base (21), an insulating gasket (22) and a power contact plate (23) so that the heatsink housing can be mounted on a traditional receptacle to replace the conventional electric bulb.