More and more vendors think of blending XML data management into traditional relational database, with the increasingly widespread use of XML. This requires a comprehensive evaluation methodology to evaluate the XML engine on a RDBMS correctly. Through analyzing XML engine on RDBMS from various aspects, the article gets a conclusion that the evaluation on it should be from several major aspects such as storage, query and update. Also, the researcher designs a complete evaluation framework who covers all the provisions of XQuery W3C standard.