Abstract: This article mainly discussed how to break through the limitation of version recovery and conduct complicated structure inquiry in any version of XMI_ documents. Surrounding the thesis, it introduced the common method of current XMI_ document version management, then brought out and implemented a new index method based on numbering schema of multi-version XML file,finally refered structural joining algorithm into XML version control field and improvedthree classical structure joining algorithm,all of which support complicated structure inquiry without version recovery.We analyzed and compared their searching efficiency by experiment, and proved that index searching algorithm can avoidredundancy in searching as much as possible.

Key words: XML, Index, Multiversion XML, Structural Join