Business organizations today have sought management effectiveness and efficiency utilizing information technologies. In particular, small and medium-sized enterprises short of information resources tend to rely more on outsourcing for accomplishing their own information strategies. SaaS(Software as a Service) has recently become one of the powerful outsourcing alternatives. This study tries to identify the influence of the SaaS quality on the service performance and loyalty. A SaaS quality model is developed including tangibles, reliability, responsiveness, assurance, and empathy. Then they are hypothesized to have influence on the service performance defined as user satisfaction, individual performance, and organizational performance. Service performance is considered to have an impact on the loyalty to service. Findings from a survey to test hypotheses on the relationship among SaaS quality, performance and loyalty show these variables are significantly important to widespread adoption of SaaS.