This paper considers a single relay selection problem in a cooperative network with multiple source-destination and multiple relay nodes. The relay selection considers the channel gain as well as the interferences in case of sharing the resources. Although the optimal relay selection can be obtained by the exhaustive search, it is not practical because of its significant computational complexity. Therefore, this paper proposes a low-complexity relay selection method which considers all interferences which occur in the multi-source multi-destination cooperative network. We derive the simplified relay selection metric from the optimal relay selection problem. Then, we perform the relay selection based on the simplified relay selection metric using the weighted bipartite graph model. The proposed method outperforms the conventional method used in the single source single destination scenario, and previously proposed, modified best-worst method in , in terms of average overall rate. Especially, the proposed method provides more performance gain when the source-relay interference is dominant, such that the relay is close to the source node.