Abstract: With the prevalence and development of cloud computing, more and more applications are deployed on the cloud servers so as to utilize virtual resources, which can scale on-demand and are priced on a pay-per-use basis. Thus, it becomes an important research problem to ensure optimal operation of applications as well as to achieve cost-benefit provision and utilization of virtual resources. Traditional manual adjustment methods will not only increase the burden on system administrators, but also the accuracy is poor and there is a certain delay. Existing dynamic resource provision methods are mostly triggered after a runtime quality problem happens, thus involving an adaptation delay. Also, these methods neglect the negative impact of the heterogeneity of virtual resources. To address these problems, in this paper we propose a method for dynamic provision of virtual resources based on control theory. This method combines a feedforward and a feedback controller to respectively tune the number of virtual resources and the load for each virtual resource in order to achieve the optimal operation of application systems and the high-efficient use of virtual resources. An experimental study demonstrates that our method can effectively achieve optimal operation of applications as well as improve the utilization ratio of virtual resources.