By pooling the provider's computing resource and performing unified management and scheduling, cloud computing achieves elastic resource provisioning. Through network, users can access to resource services on-demand. Therefore, effectiveness of dynamic resource management is the key to the success of cloud computing. In this paper, the requirements of dynamic resource management aligning with the NIST (National Institute of Standards and Technology) working definition of cloud computing were analyzed and the application-centric and infrastructure-centric management methods and techniques were reviewed. At last, the perfect of the future was presented.