A method and a system for redirecting a client are disclosed, the method including: sending by the client a request message to a redirect agent; returning by the redirect agent a first response message to the client, an identification of a second realm being carried in the first response message; sending by the client the request message to a second server in the second realm. The data are maintained and modified only on the redirect agent, so that the redirection service between different realms may be realized without upgrading or maintaining the client. In addition, because the number of redirect agents is much smaller than the number of clients, the operation and maintenance costs may be reduced greatly.