In this paper, a joint power and subcarrier allocation scheme in single-cell uplink OFDMA systems is proposed based on game theory. Our goal is to maximize the power efficiency of each user under peak power constraint. For the purpose, a utility function is designed which can enhance the rate per joule of energy consumed greatly, and the existence and uniqueness of the Nash equilibrium of the function is proved. To bring Pareto improvement, and to overcome the far-near effect, the pricing scheme is introduced. The simulation results show that the power efficiency of the proposed algorithm increases greatly over that of the MaxRt+WF (maximal marginal rate subcarrier and waterfilling power allocation) and MaxFA+WF (fixed subcarrier allocation and waterfilling power allocation).