Abstract: The paper takes the Wudongde reservoir bank landslide as an example and fully considers the developed geological environment. The four impact factors including development feature of landslide， bank slope structure and lithology characteristics， geological structure and topography characteristics， disaster inducing factors are selected as landslide susceptibility factors. A single-factor grading standard is established to divide the susceptibility of reservoir bank landslide disasters into four levels: severe， moderate， mild and good. Based on the interval number and set pair analysis theory， a new model of connectional expectation for landslide susceptibility evaluation is introduced. This model can be used to analyze variation trend of landslide impact factors. The case study shows that the new method is reliable and can simplify the analysis process of the relationship between interval numbers.

Key words: geological disaster; reservoir bank landslide; susceptibility; interval number; set pair analysis