A mobile terminal and group chat controlling method thereof are disclosed, by which a chat content transceived in an performed group chat after a join-impossible state can be received in the course of performing the group chat if impossible to join the group chat. The present invention includes performing a group chat with a plurality of counterparts, displaying a chat window of the performed group chat, if the mobile terminal is impossible to join the group chat (i.e., if the mobile terminal enters a join-impossible state) in the course of performing the group chat, receiving chat contents transceived among a plurality of the counterparts in the performed group chat after the join-impossible state, and displaying the received chat contents.