A method and system for supporting an XQuery trigger in XML-DBMS based on relational DBMS is provided. In an Ubiquitous environment where XML data are incessantly generated by an enormous number of objects, so as to overcome inconvenience and its resultant reduction of performance in which a user should query after checking a change of XML-DBMS one by one, in XML-DBMS based on relational DBMS, the present invention supports an XQuery trigger technique based on SQL trigger automatically executing insert, update and delete statements, and a storage or external procedure related with the change of data when a change of data is generated at a specific table in a conventional relational DBMS.