The present invention provides a light emitting diode lamp, which includes
at least a light emitting diode and a control circuit. The light emitting
diode lamp has an anode pin, a cathode pin, and a synchronous pin. The
anode pin and the cathode pin receive a DC voltage, and the synchronous
pin is connected to the control circuit. Moreover, the present invention
provides a synchronous light emitting diode lamp string, which includes a
plurality of light emitting diode lamps and at least a power adapter.
Each light emitting diode lamp has a synchronous pin, and all synchronous
pins are connected together. The control circuit can control the color
changing of the light emitting diode based on a reference signal from the
synchronous pin.