Abstract: In order to solve the problems of system capacity and user fairness in orthogonal frequency division multiple access adaptive resource allocation at the base of rate adaption, a scheme which adopts the two steps of the subcarrier allocation and the power allocation is presented. This scheme is mainly achieved by the subcarrier allocation algorithm based on fairness and the power allocation algorithm based on penalty function. In the subcarrier allocation algorithm, the capacity of the system can be improved when the fairness constraint is satisfied, otherwise the fairness of the user can be improved. However, the system capacity and user fairness cannot be better balanced after the subcarrier allocation. In view of this problem, a power optimization strategy based on penalty function is proposed in the power allocation algorithm, and this strategy takes advantage of the improved artificial bee colony algorithm based on the simulated annealing to achieve the tradeoff between the system capacity and the user fairness. The simulation results show that the proposed scheme cannot only improve the system capacity effectively but also achieve a given fairness constraint. Therefore, the effectiveness of the proposed scheme is proved.