Key agreement protocols allow two or more participants exchang information over an open network with each other. In modern collaborative and distributed applications, authenticated group key agreement is one of the important issues. Recently identity-based authenticated key agreement protocol has been increasingly investigated because of the simplicity of a public key management. In this paper, we propose an authenticated three-round identity-based group key agreement protocol. The first round is for identity authentication, the second round is for key agreement, and the third round is for key confirmation. The proposed protocol is based on the protocol of Burmester and Desmedt, and the protocol is provably-secure in the random oracle model. In particular, the proposed authenticated identity-based group key agreement protocol provides a batch verification technique, which verifies the validity of transcripts from other group players simultaneously.