1. A method of discovering and analyzing structures of user groups in a microblog, characterized in comprising: acquiring information on behavior data of microblog users of a target group; constructing a microblog user association network based on the information on behavior data of the microblog users of the target group; acquiring at least one maximal clique from the microblog user association network; acquiring at least one core clique based on the maximal clique; conducting behavior analysis on the user groups in the microblog based on the acquired maximal clique and/or the acquired core clique.