XML document repositary system(XDRS) should be able to manage vertical and horizontal versions of documents to store, update and manage XML documents without loss of information, However, most of existing XDRSs do not support a versioning method Although a few systems support versioning method. they only manage vertical versions of XML documents, While the vertical versioning preserves the update history of documents. the horizontal versioning branches a document to many other versions of documents so that users can easily create new documents from the original version and edit them to have different meanings. In this paper, we propose a new version numbering scheme to support both vertical and horizontal versioning efficiently. We also design a schema that supports versioning and preserves the paradigm of structure information.