The rapid increase of multimedia data makes multimedia query more and more important. To better satisfy users’ query requirements, developing a functional multimedia query language is becoming a promising and interesting task. In this paper, we propose a graphical multimedia query language called GMQL, which is developed based on a semi-structured data organization model. In GMQL, we combine the advantages of graphs and texts, making the query language much clear, easy to use and with powerful expressiveness. In this paper, we first present the notations and basic capabilities of GMQL by query examples. Second, we discuss the GMQL query processing techniques. Last, we evaluate and analyze our multimedia query language through the comparison with other existing multimedia query languages. The evaluation results show that, GMQL has powerful expressiveness, and thus is much applicable for multimedia information retrieval.