Riparian buffer zones enhance the quantity and quality status of water, stabilize channel geometry, and provide tree roots and woody debris for habitat. To establish the riparian buffer zones and to improve the water quality, privately owned lands in the Paldang watershed area needs to be purchased. A growing number of policy makers are faced with the problem of identifying an efficient and suitable location for implementing or restoring the buffer system. In this research, the Prioritization Index System(PIS) was developed and applied as a possible solution to such questions. PIS can also be used as a decision support system in the planning phase. In PIS, the Analytic Hierarchy Process(AHP) was utilized to estimate prioritization. Further data loss was avoided and maximum accuracy in space was achieved by combining the Fuzzy theory and AHP. PIS may be used to select a suitable location for riparian buffer system. Finally the results of PIS should be carefully observed to make sure that the results are consistent with the decision makers' proposed regional level indication for buffer systems and with their economical and geological point of view. The spatial decision making techniques presented here can effectively draw the weight of each criterion and quantify the prioritization of each lot, reflect the spatial condition in reality and flexibly cover local needs. It can be widely utilized in the management and prioritization in riparian zone.