In cloud computing, the service providers often take different strategies in allocating resources in IaaS through composition. This phenomenon will affect the performance of composition process. Moreover, when different consumers apply for the same types of services, the fundamental problem of how to effectively allocate and schedule the services with consideration of various service characteristics rises. Therefore, this paper discusses the gaming behaviors of service composition in cloud computing based on game theory. Through investigating the gaming behaviors of winning cost in different players, A SLA-based service composition algorism is proposed.