In the cloud computing, idle resources can be integrated and allocated to users in the form of service. A resource allocation mechanism is in need to effectively allocate resources, motivate users to join the resource pool and avoid fraud among users. Unfortunately, there is little literature addressing this issue. In this paper, the authors tackle this issue by introducing microeconomic methods into the resource management and allocation in the cloud environment. With the combination of batch matching and reverse auction, a reverse batch matching auction mechanism is proposed for resource allocation.