Based on modeling and simulation for complex systems, a new approach to predict networked software systemavailability was proposed by multi-agent system modeling and simulation. Firstly, the method of multi-agent systemmodeling and simulation was introduced. Secondly, the characteristics of reconfiguration networked software systemwere analyzed. And then after researching on the approach to multi-agent based modeling and simulation for networkedsoftware system and behavioral models of reconfiguration, the new strategy which can be used for availability predictionwas addressed. Finally, in order to verify the effectiveness, a case study was taken based on the approach, which was rea-lized on the Netlogo simulation platform.