Abstract: Clarifying the relationship between cloud computing and SOA is significant to the application and combination of them. This paper surveyed their relationship, and on this basis, the differences and relations between cloud computing and SOA were analyzed. In addition, different views from enterprises and the latest academic researches about their relationship were summarized, and the approaches combined with SOA to integrate cloud services were proposed.First, it's possible and essential for them to combine. Furthermore, the main combinations between them were analyzed. Second,this paper divided possible opportunities and challenges of combinations into several groups discussed in detail respectively. Additionally, the methods to solve these problems were further analyzed. At last, concrete integration needs were proposed, and the integration methods of SaaS and PaaS by adopting SOA were introduced respectively. Further work of realizing the integration of SaaS by adopting SOA was also discussed.

Key words: Cloud computing, SaaS, PaaS, Cloud service integration, SOA