The traditional vendor selection model often pay attention to the profit of the buyers and the selection behavior of vendor is ignored,but the vendors only trade with the buyers according with their rational selection,so the vendors selection bi-level programming model is presented with constraint of minimal batches,the ability of supply,product matching etc.A solution of the model based on genetic algorithm is proposed.The buyers' vendor selection of minimum cost is realized in the upper programming and the allocation of requirements is proposed in the lower programming.The application of the model and its algorithm are illustrated with a practical example.