This article aims at applying spatial multi-criteria decision analysis for landslide risk area delineation. It is obvious that the methods used previously are lack of theoretical foundation which leads to imprecise results. Therefore, the new technique is introduced in spatial decision making analysis which consists of analytical hierarchical process and fuzzy set membership function. The methodology is applied to delineate landslide prone area in Petcaboon province. It is found that the fuzzy set membership values of each attribute range from 0 to 1 according to its property. The criterion weight of slope, soil texture, landcover type, distance from stream, rock type and rainfall are 0.4105997, 0.297540, 0.130632, 0.093428, 0.03992883 and 0.02787083 respectively. Having aggregated the standardized criterion map, it is found that the landslide prone area exists in 6 amphoes, namely Lom Kao, Lom Sak, Khao Ko, Nam Nao, Muang and Wang Pong.