A LED lamp includes a main body surrounded by a fin assembly on the periphery at an upper side and a lower side, a power supply holder located at the upper side and a plurality of LED lamp assemblies located at the lower side. The LED lamp assemblies are encased by a light converging plate which is further encased by a transparent lamp shade fastening to the lower side of the main body. The LED lamp thus formed may be fastened to a ceiling for indoor use through an upper cap of a fastening assembly, or an outdoor electric wire pole through a fastening tray. Each of the LED lamp assemblies has a heat transfer tube to transfer the generated heat to the main body for dispersing through the fin assembly. Thus desired heat dissipation can be accomplished.