In DTNs, nodes do not have endtoend connections for long periods of time. Therefore,in order to provide reliable communications in the intermittent connection environment,intermediate nodes are required to store data packets for long periods of time. Enough buffer capacities and energy is the key to work of DTN network.The dispersion of nodes to make it difficult to implement. in this paper, we propose a social grouping based protocol(GBP) among the network nodes to maximize data delivery ratio while minimizing network overhead by efficiently spreading the packet copies in the network. Firstly, we introduce the principle of GBP, then using Opportunistic Network Environment (ONE) simulation software to compare the performance of Epidemic algorithm, Spray and Wait algorithm, PRoPHET algorithm, MaxProp algorithm and GBP. By comparing packet delivery cost, rate of messages delivered and average dealy, it finds that the GBP performs better. At last, the weaknesses of this paper and further improvement are also discussed.