Abstract: The emergency power system is one of the essential systems which assure the safety of China Advanced Research Reactor (CARR). The function of the emergency power system relies on its high reliability. The research on the reliability of emergency power system was carried out in this paper, using the reliability analysis methods including failure mode effect analysis (FMEA) and fault tree analysis (FTA). Carrying out qualitative and quantitative analysis of the emergency power system by building relevant models, the fault probability and minimal cut sets were obtained. Finding out the weakness, effective suggests and measures for improving the reliability of emergency power system were brought forward. The results in this paper can provide the support for the safe and reliable operation of CARR.