A light emitting diode (LED) lamp includes a heat dissipation module, a circular light guide plate (LGP), and LED light sources. The heat dissipation module includes a heat dissipation element and a heat-conducting base that has a containing concave. The heat dissipation element connecting and surrounding the heat-conducting base is distant from the circumference of the heat-conducting base. The circular LGP in the containing concave has a top surface, a bottom surface, and an annular side surface. The top surface faces the heat-conducting base and has concentric annular trenches. The LED light sources are configured in the containing concave and face the annular side surface. The LED light sources are suitable for emitting a light beam which is capable of passing through the annular side surface to enter the circular LGP and capable of being reflected by the annular trenches and emitted from the bottom surface.