Recently, there has been plenty of interest in XML. Since the amount of data in XML format has rapidly increased, the need for effective storage and retrieval of XML data has arisen. Many database researchers and vendors have proposed various techniques and tools for XML data storage and retrieval in recent years. In this paper, we present an XML data management system using a relational database as a repository. our XML management system stores XML data in a schema independent manner, and translates a comprehensive subset of XQuery expressions into a single SQL statement. Also, our system does not modify the relational engine. In this paper, we also present the experimental results in order to demonstrate the efficiency and scalability of our system compared with well-known XML processing systems.