Abstract: Current Internet is designed based on end to end principle and co-established by lots of Internet service providers with different objects and policies. In order to update Internet architecture, it needs to reach a consensus among almost all of them, which makes the direct deployment of radically new architecture and protocols on Internet nearly impossible. To fend off the ossification of Internet architecture, network virtualization is proposed to add diversity in the future Internet. By introducing various architectures on a common substrate network, Internet virtualization can promote Internet innovation and encourage the emergence of huge kinds of new applications. In this paper we firstly describe the application context of network virtualization and the general virtualization method of traditional networks, then setup a classification framework for various related researches on Internet virtualization. After that we explore them one by one from the perspectives of both Internet architecture and test bed, and summarize the development trend of research on future Internet virtualization. We conclude that network virtualization is an indispensable part of future Internet and takes two roles in it. One is for underlay network, the other is for each future Internet paradigm, and both of them are required for future Internet to realize its design goals.