Abstract: In this paper, through the analysis and study of simple genetic algorithm(SGA) and its research state and through the comparison and analysis of the characteristics of complex system and SGA, the author suggested a new multiagent-based genetic algorithm, defined the SGA's environment, agent structure, genetic operator, target/evaluation function, and flow chart. At last ,the author verified this new GA with a test function and a multiapex function in complex environment. The results indicated that this new GA had many merits and advantages, suiting to resolve the problems of complex system.