Cloud computing is evolving as an important IT service platform with its benefits of cost effectiveness and global access. To become a widely adopted IT infrastructure and service platform, cloud computing has to be integrated with other systems in organizations. In academia, there is very limited study of cloud computing integration. In practice, the industry lacks comprehensive systems integration architecture or tools that can integrate any system universally. Built upon Enterprise Service Bus (ESB) as an integration backbone, this paper proposes universal integration architecture. With this architecture, any system or service (e.g., ERP and cloud computing) can easily be integrated through the ESB without needing software redevelopment.