The problem of coordinated supplier selection and quantity allocation based on the joint replenishment policy is studied, and an effective and improved differential evolution (IDE) algorithm is proposed to solve the problem. Then a new coordinated supplier selection and order quantity allocation model considering grouping constraint caused by the heterogeneity of items is developed. Results of contrastive numeric examples show that the IDE algorithm outperforms the standard DE algorithm and the simulated annealing(SA) algorithm in solving this problem and its extension type. The effectiveness of the IDE algorithm is further verified by randomly generated large-scale numerical examples.