Abstract: The saturated permeability coefficient of soil is an inherent variable due to its inhomogeneity and the inaccuracy of monitoring. To explore the stability and failure probability of bedrock laminar slope under heavy rainfall, a reliability analysis model of bedrock laminar slope is founded based on the Monte Carlo method and the model for rainfall infiltration and stability analysis developed by the authors, and the variability of saturated permeability coefficient of slope soil is considered in this reliability analysis model. To calculate the failure probability, the whole process is realized based on MATLAB. At the same time, the failure probability of Zhangjiawan landslide under different variation coefficients of saturated permeability coefficient and different rainfall intensities is analyzed by using the reliability analysis model, and the influences of variation coefficient of saturated permeability coefficient and rainfall intensity on failure probability and safety factor are analyzed. The results show that the larger the variation coefficient, the greater the failure probability of Zhangjiawan landslide when the failure probability is less than 50%. However, the smaller the variation coefficient, the greater the failure probability of Zhangjiawan landslide when the failure probability is greater than 50%.