For an identity-based authenticated key agreement (IDAK) protocol, PKG forward secrecy is the strongest notion of forward secrecy, which is about the security of previously established session keys after the master secret key of the Private Key Generatior (PKG) is compromised. In this paper, we put forward a new identity-based authenticated key agreement protocol which achieves PKG forward secrecy. On its performance, we show that it is more computational efficient than a previously proposed protocol of Chen and Kudla (called Protocol 2 ). Furthermore, we examine other security attributes that our new protocol possesses one bye one.