A communication management system manages communication terminals transmitting and receiving communication data. The system includes a session management unit configured to manage session identifying information and terminal identifying information in an associated manner, the session identifying information being used to identify a communication session being performed among a plurality of communication terminals and the terminal identifying information being used to identify each of the communication terminals; a receiving unit configured to receive, from a conversion system, terminal identifying information about a communication terminal that is being in communication, the conversion system mutually converting a communication scheme of communication data transmitted from one communication terminal and a communication scheme of communication data transmitted from another communication terminal; and a transmitting unit configured to transmit, to the conversion system, session identifying information that is associated with the received terminal identifying information in the session management unit.