We developed a passage retrieval system for XML documents using the vector space model. To be more flexible for the query, we also developed a method of unification of multiple retrieved elements and a fragment indexing system. Our system is composed of an inverted file and an XML Path Language (XPath) path list. The validity of the method was tested as part of the ad hoc track in the Initiative for the Evaluation of XML Retrieval (INEX) 2006.