Many methods for mapping XML to relations have been proposed without considering the semantics of XML data before. But the semantics is very important to design schemas for storage, optimize queries, and check update anomalies, etc. In the presence of XML FDs which are specified over DTDs, this paper presents a method based on the hybrid inlining to map XML to relations for storage. The constraints which are represented by FDs, as well as the content and the structure, are preserved at the same time. Much storage redundancy can be reduced through using this method. Furthermore, this paper proves that those relations mapped from XML are all in Third Normal Form (3NF).