A system based on Orthogonal Frequency Division Multiple Access (OFDMA) has been developed to deliver mobile broadband data service at data rates comparable to those of wired services, such as DSL and cable modems. When flows pass through relay stations in OFDMA network, plenty of network coding opportunities arise and leveraged to enhance throughput. Here, the proportional-fair scheduling problem in the presence of network coding in OFDMA relay networks is studied. The proposed approach uses heuristic algorithm and greedy algorithm to solve the problem. As a result, it improves the network throughput and time complexity.