Abstract: On view of database,the article analyzes the indirect functional dependency，transitive functional dependency and MVD in XML,elaborates the XNF-1,XNF-2 and XNF-3,which are corresponded by the normalization of the indirect functional dependency,transitive functional dependency and MVD respectively,and puts forward four principles of file normalization.Taking the property elements into consideration,the article also probes into the feasibility of anti-normalization.

Key words: XML, database, functional dependency, normalization, anti-normalization