Abstract：In the finite element analysis，the soil is assumed to obey realistic elastoplastic and Mohr-Coulomb yield criterion. Based on the technique of sliding surface stress analysis and on the theory of elastoplastic finite element，the stress and the derivatives of the stress of the basic stochastic variables for the slope are computed by using partial differential technique and incremental initial stress method. In the reliability analysis，the limit state function is set up which can consider the direction of the sliding surface. And then the reliability indices of the whole slope are computed using the first order reliability method(FROM). In order to improve the efficiency of the computation of the reliability indices，it¢s necessary to carry out sensitivity analysis. Therefore，the formulas of the sensitivity of reliability indices to the basic parameters in the original space when they are correlated are derived. The advantage is that the transforming matrix，which is needed in the computation in the transformed space，is now unnecessary in this method. Considering the differences of the units of each parameter，the relative sensitivity formulas are suggested. An example is given to illustrate that the reliability indices calculated by this paper are the same as those of strength reduction method(SRM)；and reliability indices got from FORM are a little larger than those of mean first order reliability method(MFORM). Through sensitivity analysis，it¢s concluded that the effects of parameters c，j are much larger than the others；and their effects on the reliability indices increase when the negative coefficient of correlationship of c，j become large.
