Abstract: For the solution of resource allocation in the cellular and D2D communication hybrid networks could be formulated into an optimization problem with the objective of maximizing network throughput, a two-step resource allocation scheme was further designed based on this model. First, the resource blocks were assigned to the users with an improved greedy spectrum allocation algorithm. And then, the dual-decomposition based algorithm was employed to allocate optimal transmission power for each resource block. Moreover, based on consideration of QoS requirement for cellular users, the proposed algorithm no longer restricted the number of D2D users on each resource block and resources reused by D2D user. The simulation results show that, the proposed algorithm makes an effective improvement in capacity of whole system while still retains the rate of cellular users.