An LED lamp includes a housing, at least one circuit board, several LED and two electric wires. The LED are mounted on a bottom face of the circuit board. The circuit board and the LED are all installed in the housing with the LED located at a bottom end of the housing. Two through holes are formed on a top end of the housing. The electric wires respectively passed through the through holes of the housing to electrically connect with the circuit board. The LED lamp is inbuilt with LED so that it is unnecessary to further install any LED bulb. The electric wires can be serially connected so that multiple LED lamps can be easily connected.