In order to fully describe the properties of cloud manufacturing resources and implement the mapping and transformation of physical resources to virtual ones,the service architecture of cloud manufacturing as well as the characteristics and categories of manufacturing resources is taken into consideration,and the virtualization principles of cloud manufacturing resources,such as the systematicness,the pertinence,the adaptability,the expansibility,the interface uniformity and the dynamism,are pointed out.Then,manufacturing equipment resources are exemplified to characterize the model,and a template for resource virtualization is presented by extending the Java class in open source software CloudSim.Finally,by taking a part machining service as an example,the virtualized manufacturing resources are unified as cloud services by using the open source software Tuscany SCA,and the cloud services are registered in the service registry center for the discovery and invoking of cloud manufacturing resources by users.