Small and medium landslides are widely distributed, the prediction mainly relies on the monitoring and controlling systems executed by the masses. The advantages and disadvantages of various stability assessment methods are compared. The engineering analogy method accords with the requirements for small and medium landslide assessment. A method is illustrated based on Fisher discrimiant function to cope with the small and medium potential landslide stability assessment. The impact factors of landslides is explored with the historical data. The stability is taken as a multi-dimensional statistical variable and project into one-dimensional straight line. Distance discriminant method is used to construct a classification criterion. The applicability of this method is explored, and assessed the landslides in Chongqing Wulong by this method. The results show that accuracy of this method is about eighty percent. This method is suitable for the city of Chongqing or other areas with the similar geological environment.