In- and out-doors LED is a new device with excellent performance in power-saving, lighting efficiency, reaction time. Currently, it is widely used in communication, display, illumination. Reliability is a key point to promote its application. The most important reliability issue in LED modules is about packaging which includes refrigeration, bonding wire, the aging of organic material, good packaging design et al. In this paper, the failure modes and failure mechanisms of LED are reviewed, and some failure analysis cases are presented.