Vehicular network can support road safety and traffic efficiency by vehicular-to-vehicular (V2V) and vehicular-to-infrastructure (V2I) communications. In this thesis, we propose an improved resource-sharing algorithm which can make some communication links share a resource block under the circumstances of each link having promised SINR to increase the throughput. In vehicular network, the high speed environment, computation time of an algorithm is extremely important. So we propose a selective algorithm to make more links share the resource block, increase the throughput, and decrease the complexity of the algorithm. Through the simulation result, we can present our algorithm not only decrease the time it cost, but make more links share the resource block, and increase the throughput at the same time.