Cloud Computing has emerged as a new paradigm that permits to deliver Information Technology resources on demand and outsource software and hardware infrastructure. To support dynamic load, the system should select the best location for serving the request to achieve best performance. Selection of data center plays an important role to improve the performance as well as to reduce the cost. Service broker controls the traffic routing between user bases and data centers based on different service broker policies. In this paper we propose a new service broker algorithm which combines the cost and efficiency for optimized the cost and response time.