Suppliers become an essential factor of enterprise competitiveness. The analytic hierarchy process is a kind of Decision-making method with the combination of quantity and quality. This paper presents the evaluation system of supplier selection, using Analytic Hierarchy Process (AHP) method to select the optimum supplier in Enterprise Resource Planning (ERP) enterprise. In order to reduce factor of manmade and increase exactitude, this paper innovates to use a real database in ERP system for evaluation. It also gives an example that one enterprise selects supplier.