Enterprise Cloud Service (ECS) becomes the major aspects of enterprise information system development and application integration. One of the most important challenges in ECS is the lack of a de facto standard or single architectural design method, which can meet the application requirements of an enterprise cloud approach to help deliver software as a service over the Internet. First, aiming at the traits of enterprise business, the definition of enterprise cloud service is given by the extended formula. Then, based on above mentioned definition, a cloud service framework for enterprise information system is proposed, and the enterprise cloud service is also discussed from six aspects such as service type, service deploy, service process, service management, service quality, and so on. Finally, the application instance of ECS is introduced, which hopes to provide recommendations and reference for development of ECS in enterprises.