XML has emerged as a standard format for data representation and information exchanges on the web.The development of XML databases made it possible to store the entire XML document in a database system. Since such XML document usually contain important enterprise information, the control of access to an XML database becomes an important research issue. Access control are usually specified by a policy document. In this thesis, we adopted the architecture for XML database access control are described in [1]. We then transform an XACML policy into XSLT, to improve efficiency for accessing an XML document.