Proposal of cloud computing is tightly coupled with low cost. Reduction of cost is considered as an important advantage of cloud. However, there are no available tools proper for cost calculation and analysis in Cloudenvironment. This paper presents our efforts towards filling in the gap. We format suits of metrics and formulas for the calculation of Cloud Total Cost of Ownership(TCO) and Utilization Cost, considering the elastic feature of Cloud infrastructure and widely adopted virtualization technology in Cloud. This provides afoundation for evaluating economic efficiency of Cloud and provides indications for cost optimization of Cloud.We have developed our calculation and analysis approach into a web tool which is used in the internal Cloud environment and demonstrate initially its analysis capability on the cost distribution and utilization imbalance factor.