Abstract: Rather than trying to tie together manufacturing resources for the purpose of creating an aggregated application to perform,cloud manufacturing seeks to aggregate manufacturing resources from various distributed manufacturing entities into a virtual pool of resources by using virtualization technique,and to expose manufacturing resources as a set of services that resources consuming applications and organizations can combine in any arbitrary fashion.To ensure precisely scheduling and using of the capabilities provided by manufacturing resources through cloud manufacturing services invocation,it requires the virtualization process from manufacturing resource to cloud manufacturing service must guarantee the capacity described by cloud manufacturing service is strictly consistent with the original one provided by the relevant manufacturing resource.In this context,a homomorphic mapping based virtualization mechanism for manufacturing resource is proposed,which is built on a three-layer model including physical resource layer,virtual capability layer and cloud service layer.On the basis of the decoupling of the direct mapping between physical resources and cloud services via establishing virtual capability layer,the mechanism meets the requirements of virtualization process by defining two homomorphic mappings:mapping between physical resource and virtual capability,and mapping between virtual capability and cloud service.The discussion is made from case demonstration to provide evidence of the benefits from homomorphic mapping in the context of keeping mapping invariance for the virtualization process and ensuring the validity and reliability of cloud manufacturing service.