中文摘要：

云计算的发展，对提高服务质量与压缩运行成本提出了新的要求．在此背景下，工作流技术被认为是一种较为优越的解决方案：从云计算用户的角度看，工作流提供了对复杂应用的抽象定义、灵活配置和自动化运行；从云计算服务提供者的角度看。工作流实现了任务的自动调度、资源的优化和管理．文章介绍工作流技术与云计算；阐述了云工作流产生的背景；深入剖析了云工作流的技术特征以及与其他工作流（业务工作流、网格工作流）的异同；列举了云工作流的4个实现案例，并对其进行比较．最后，在总结全文的同时，展望了云工作流技术的发展前景．

英文摘要：

Along with the development of Cloud Computing, improving OoS （ Quality of Service） as well as reducing OC （ Operation Cost） is increasingly becoming an urgent goal. Cloud-oriented workflow technology is now regarded as a pretty good solution： For users of could computing, cloud workflow enables a complex application instance to be abstractly defined, flexibly configured and au- to-operated; for enterprises who provide cloud services, cloud workflow brings them auto-scheduling of tasks, optimization and man- agement of computing resource. This paper proposed a short introduction to the technology of both workflow and Cloud Computing; Introduced the background in which Cloud Workflow generated; Meanwhile, the following part fully compared Cloud Workflow with other workflows （ Business Workflow and Grid Workflow） according to the technical characteristics of workflow; After that, 4 instances of Cloud Workflow management system are listed, as well as their similarities and differences. At the end of this paper, a summary, and predicted the possible trend of Cloud Workflow in the future are given.