Abstract: The nonpreemptive real-time periodic tasks scheduling on variable processor is mainly concerned in this paper.Based on genetic algorithm （GA）,a heuristic algorithm is proposed to make the random search naturally meet the energy and timing constraints,as well as maximize the system reward. Experimental results show that GA has obvious advantages over greedy algorithm on reward improvement. It reveals that energy efficiency increases when the energy budget decreases,which proves the energy awareness of the scheduling algorithm.