In recent years, a large number of identity-based key agreement protocols from pairings have been proposed. Some of them are elegant and practical. However, using most of those protocols, the session key which users arrive is depended on the identity information. In this paper, we first propose a two-party identity-based key agreement protocol based on pairings whose security relies on the hardness of the bilinear Diffie-Hellman problem in the random oracle model, and the session key is independent of the identity information. After that we extend the protocol to an identity-based group key agreement protocol, which uses no broadcasting. The proposed key agreement protocol achieves the security attributes: known session key security, perfect forward secrecy, no key compromise impersonation, no unknown key share and no key control.