Abstract: Seismic probabilistic risk assessment could be respectively conducted using analytical function of seismic risk and risk convolution function. In this paper, analytical function of seismic risk was conducted, two basic assumptions and two approximations of analytical function of seismic risk were analyzed, and seismic probabilistic risk analysis of a nuclear power plant containment of our country were respectively conducted using analytical function of seismic risk and risk convolution function. The results show that there is no influence on seismic risk results using a power exponent function approximating seismic hazard distribution following extreme value Ⅱ type distribution. For the case of this paper, seismic risk of a nuclear power plant containment is overestimated based on analytical function of seismic risk, which uses constant KH and kⅠ. Seismic risk of a containment is low in our country, which has a large safety margin. It is proposed that the preliminary seismic risk assessment of a nuclear power plant containment of our country using analytical function of seismic risk should be conducted.