Abstract: This paper analyzed the common key agreement protocol.Based on the homomorphic encryption mechanism and NTRU Public Key Cryptosystem,the authenticated homomorphism key agreement protocol based on NTRU Public Key Cryptosystem was presented.The session key created by the that protocol was authenticated,contributory and forward secrecy.Compared with the key agreement protocol based on the other public key cryptosystem,it has better security and efficiency.The improved BAN logic was used to analyze the protocol formally,and the security of the protocol was proved.