The present invention relates to a security management method and an apparatus for group communication when a terminal interacts and communicates with a mobile communication system. The security management method for group communication performed in a server, which manages the group communication in the mobile communication system according to one embodiment of the present invention, includes the steps of: generating a session security key for session protection in the group communication, and mapping the session security key to a group identifier for identifying a specific group to which a terminal using the group communication belongs; transmitting the group identifier and the session security key to the terminal; and generating a traffic key for protecting traffic and transmitting the group identifier and the traffic key to the terminal.