A downlink radio resource allocation algorithm is proposed for orthogonal frequency division multiple access( OFDMA) systems. The resource allocation problem about system throughput and user fairness is formulated based on the multi-objective optimization theory. Then the optimality conditions are derived,according to which a joint subcarrier and power allocation algorithm is proposed. The simulation results show that the proposed algorithm can dynamically achieve arbitrary levels of compromise between throughput and fairness by adjusting the weighting coefficient,outperforming some static algorithms. In comparison,the classic maximum rate algorithm( MRA),max-min algorithm and proportional fairness( PF) algorithm can only achieve tradeoff in a certain level and are all special cases of the proposed algorithm. A downlink radio resource allocation algorithm is proposed for orthogonal frequency division multiple access (OFDMA) systems. The resource allocation problem about system throughput and user fairness is based on the multi-objective optimization theory. Then the optimality conditions are derived, according to which The simulation results show that the proposed algorithm can dynamically achieve arbitrary levels of compromise between throughput and fairness by adjusting the weighting coefficient, outperforming some static algorithms. ), max-min algorithm and proportional fairness (PF) algorithm can only achieve tradeoff in a certain level and are all special cases of the proposed algorithm.