Abstract: Spectrum sharing for cognitive radio between primary users and secondary users base on game theory was presented. For enhancing the profit of primary users, primary users sell the idle spectrum to secondary users in the cognitive radio networks. The secondary uses compete for the spectrum offered by the primary users. Because secondary users have different detection capabilities, the positivity that primary users share the spectrum with secondary users was also different. In this paper, the priority of secondary users was set based on their detection capability, which was effectively reflected by the remainder percentage of secondary users' battery energy. Then, a new utility function was obtained when the value of the battery energy was put into the price function. Numerical results show that the spectrum is allocated more effectiveness, fairness and rationality of the proposed equilibrium algorithm.