Fault tolerance is critical to computer systems. Recently,as the ever increasing complexity of architecture and the development of semiconductor techniques,the density of chips becomes much higher. As a consequence,the reliability issue of computer systems emerges,not only for largescale parallel systems,but also for distributed environments,even desktop applications. This paper reviews a number of typical faulttolerance techniques concerning hardware faults proposed in recent years,especially for those designed for largescale parallel systems,draws some preliminary conclusions,and puts forward several potential  research topics of this domain.