Endpoint Admission Control technology takes authentication and security state checking on endpoints accessing to network on the basis of pre-determinate security policies. It makes sure that only the trustworthy and secure endpoints could access to networks while rejects or limits the accessing of insecure endpoints. It’s exemplification of the combination of Endpoint Security and Access Control, which can efficiently improve the active defense ability against security threaten of networks. However, the existing solution has shortages in authentication and security state checking that it could easily attacked by Man-in-the-Middle Attack and Session Hijack. What’s more, it also has limitation in Virtualization appliance as well. It’s considerable to consummate the mechanism of authentication and communication processes for improvement.