In this paper we propose a new method to store an XML document in an object database (DB). First, the document’s DTD is mapped into a DB schema, then the XML document is mapped into a DB instance. Our method stores the element-subelement relationships and the element attributes. It takes into account the order and the cardinality of subelements. It keeps track of the groupings in an element, and alternatives among subelements. Our method allows us also to retrieve back the DTD and the entire document from the database without loss of information. We implemented our method in the F2 database system, and tested it on sample XML documents