关键词: 服务质量，云计算，服务等级协议

Abstract: Cloud computing is an emerging network computing paradigm, which focuses on the services. Cloud computing aims at providing its customers with a content quality of service (QoS) and thus researches on QoS-driven cloud has been an demanding topic. Based on the quality of services, the basic theory and status of Qo}driven researches relevant to cloud computing are introduced. Then, the key frameworks and techniques on QoS-driven cloud are discussed.Some problems of the cloud computing environment concerning QoS are put forward in the end.

Key words: Quality of service(QoS),Cloud computing,Scrvice level agrecment(SLA)