— This paper introduces a resource allocation strategy which focuses on minimizing power consumption in Orthogonal Frequency Division Multiplexing(OFDM) systems. In case of multicasting systems, it is appropriate to allocate resource with power saving strategy, since the effect of frequency selective channel is ignorable. By this strategy, the number of OFDM symbols MSs receive is minimized. A great amount of power can be saved, because the radio frequency and baseband processes are the dominant factors of power consumption. This paper also proposes a heuristic algorithm for finding the suboptimal solution of resource allocation with low complexity. By this algorithm, resource allocation process requires O(n3 ) computations with little performance degradation. The numerical analysis and simulation results show that the performance of this algorithm is close to the optimum.