The paper proposes a mathematical model to determine the optimal logistics system for farmer's association supermarkets in Taiwan. The decisions related to this optimal logistics system contain the numbers, sizes, storage style, locations and service areas of the distribution centers. Based on our research results, four normal-storage and four cold-storage distribution centers should be established in order to minimize the total cost. With the establishment of the optimal logistics system, the farmer's association supermarkets can be integrated as a chainstore so that their competitiveness can be improved.