Abstract: A distributed power control algorithm in hybrid cellular and Peer-to-Peer (P2P) network is proposed. In the objective of overall system spectrum efficiency maximization, a distributed power control scheme of P2P transmission in the hybrid system model is devised based on the tools of convex optimization. The algorithm considers the harmful interference between cellular sub-system and P2P sub-system, and provides effective interference avoidance mechanism, thus improves the total system throughput. Simulation results prove the convergence and performance of the proposed scheme.