Constant current led lamps

The utility model discloses a constant current LED lamp, which is provided with a driving device for driving at least two serially-connected LEDs or packaged polycrystal serially-connected LEDs. The driving device comprises a rectifying circuit, a filtering circuit, a voltage stabilizing circuit and a constant current circuit, wherein the rectifying circuit is used for receiving an alternating current power supply and converting the alternating current power supply into a direct current power supply; the filtering circuit is connected with the rectifying current; and if an input power supply is the direct current power supply, the rectifying circuit and the filtering current are omitted. By using the driving device disclosed by the utility model, the structure of the circuit is greatly simplified and the series connection voltage of each LED is ensured to approach to input voltage, thus each LED is driven by fully utilizing the input power supply, fully utilizing the power supply and reducing the power loss.