A method and an apparatus for network function virtualization, which may allow services of VNF components logically and physically distributed in a VNF instance to be shared with another VNF instance in a NFV environment without any separate component such as a load balancer. The method for network function virtualization includes: configuring one or plural virtual network function (VNF) instances including one or plural shared virtual network function (VNF) components and one or plural VNF instances including one or plural non-shared VNF components, generating a descriptor including attribute information of the one or plural shared VNF components, and providing the descriptor to a VNF instance which is to use the shared VNF component.