At present, storing XML document in a relational database is a hot topic because relational databases are mature and scale well. In this paper, a novel relational database storage structure that can store XML document is proposed. An algorithm that translates XML document to relational database is given according to the proposed storing structure and algorithms that translate XPath Query to SQL Query which runs on SQL Server 2000 is also given. The steps and algorithms are given in detail to describe how to use the storing structure to storage and query XML document in relational database. Then, an example is presented to show how to use this method and approve the correct of the proposed storing structure and given algorithms. Compared with other methods, the method in this paper has advantage in compact translated SQL, lesser relational database space and quicker query speed.