There is provided a communication apparatus, adapted to be used as a user terminal, connected to a message communication system in which a plurality of user terminals are interconnected, the plurality of user terminals sharing virtual worlds and avatars (symbols) of users each operating an associated one of the user terminals, and messages are exchanged among the plurality of user terminals while creating an atmosphere such that as if one's own self enters the virtual world and has conversations. In the communication apparatus, the users (symbols) are classified into a plurality of categories, and action contents of the symbols are controlled in accordance with the categories. According to the communication apparatus, a symbol with a great deal of individuality is produced, so that a virtual world full of variety may be implemented.