Cloud Computing is a service oriented computing based on pay per use technology. In generally cloud computing service requests are on demand requests. It may cause some problems like not surety about resource, high cost during demand. It may affect the user cost to pay. Optimization of cost in resource provisioning technique will be used to reduce the cost paid by the user. Here we use the reservation plan for forecasting the future required of services. It may cause the surety about the resource availability and preserve the user cost from the on time demanding cost for provisioning. In our technique we use a unique customer id to solve the Provisioning problems like under provisioning and over provisioning. To solve the problem by using the on demand request. Our Optimizing Cost in Resource Provisioning algorithm will use the stochastic programming modeling, Benders decomposition and scenario techniques to solve the problems. By using this technique we will achieve the reduced cost for user.