Abstract: Aiming at the problem that the traditional Certainty Factor(CF) method can't solve the difference of each factor in geological hazard susceptibility analysis, a Weighted Certainty Factor(WCF) method which combines the Analytic Hierarchy Process(AHP) and traditional CF was proposed. The traditional CF method was used to calculate the susceptibility index of each factor. The weight of each factor was determined by the AHP, and the final susceptibility indexes of all factors were weighted and summed to analyze geological hazard susceptibility. A GIS based comparative study of CF and WCF was illustrated at Chengcheng County, Shaanxi Province. The results showed that the WCF method was superior compare with the traditional CF method for the geological hazard susceptibility analysis. This study can provide a reference for theoretical research and application of geological hazard susceptibility analysis.