The variation coefficient and its probability distribution of combined action and combined resistance are discussed based on the statistical results of calibration calculating for reliability index β by JC method to anti-sliding and anti-overturn stability of gravity wharf as well as some typical analyses by Monte-Carlo method. The result indicates that the probability distribution of combined action and combined resistance all conform approximately to the type of lognormal or normal and then the partial factor for combined resistance can be obtained and set by them, which may serve as reference for revision of the code. On the basis of this, we submit some revision suggestions on the partial factor and the adjustment factor for structure.