Data about 400 landslides in Three-George reservoir area were collected and summarized in recent years. It is concluded that there are five types of sliding-prone strata in reservoir area on the basis of geologic analysis and engineering geology analogy analysis. Through K-S finite contrast method

test of goodness of fit was respectively carried out on 3 308 groups of shear strength parameters; and the results showed that distribution forms of parameters c and ? are normal distribution and logarithmic normal distribution. The optimum fits of probabilistic models of c are mainly logarithmic normal distribution. As there are gravels in soil in landslide zone

linear regression analysis was carried out between the gravel content and the parameter ? of soil in landslide zone and the results indicated a well positive correlation relationship.