Abstract: To solve the multi-vendor selection problem in a multi-product supply chain, an optimizationmodewas constructed with the lowest composite cost taken as the objective function and with necessary constraints. A decomposing algorithm was used to overcome the difficulty in solving the mode.l The originalmodelwas transformed into an integer programming mode.l Based on different iteration procedure, two algorithms were presented. The model and algorithms were applied in a numeral example, and an optimized assignment of the products was obtained. The proposed method overcomes the limitation in the conventional vendor evaluation models where only single product or single vendor is considered.