A method of managing the session information of an AT in a CDMA2000 1xEV-DO system. In the 1xEV-DO system, a service system, having an SC/MM, is connected to a PDSN, a plurality of ANs are connected to the service system, and a plurality of ATs are capable of wireless communication with the ANs. In the session information managing method, an AN transmits to the SC/MM a session retrieve request message, upon receipt of a connection request message from the AT. The SC/MM then searches for session information of the AT and transmits to the AN a session retrieve response message including the session information. Upon receipt of the session retrieve response message, the AN transmits a connection response message to the AT.