The present invention is to replace the original light sources with LED lamps in conventional lamp settings designed for fluorescent lamps, incandescent bulbs, and the bulb-based flash lights. It provides an LED lamp, comprising a plurality of LEDs, a circuit board for soldering said LEDs, a connecting base. The circuit board includes a plurality of solder points, each for soldering an LED, and a conductive line to electrically connect the soldered LEDs. The connecting base is electrically connected to the conductive line of said circuit board. The connecting base is also used to mount in the conventional lamp socket and make electrical connection. The connecting base is a column for encompassing the circuit board, wherein said circuit board is shaped according to the shape of the column, and the position of connecting to the column is designed according to the use in the preferred embodiments, such as fluorescent lights, incandescent bulbs, and bulb-based flash lights.