This paper addresses development of a general storage and retrieval methods for changes of XML document In this approach, histories of XML documents are modeled by TXPath data model, which is an temporal extension of XPath data model. Given an XML document, changes of the document are modeled by TXPath data model, and it is then mapped into valid-time relational tables of temporal relational database. We show fundamental operations for XML documents, which are based on DOM (Document Object Model), and also show how the operations are mapped into those on valid-time relations'. Finally, we can retrieve changes of XML documents using SQL.