The eXtensible Access Control Markup Language (XACML) is the new standards of OASIS, which describes a policy language as well as an access control request/response language. XACML serves at a high layer of the architecture in distributed application. As access control system of underlying layer, it is important to possess ability to cooperate with XACML. One of the implementation possibilities is to integrate XACML into the underlying layer. This thesis is about the integration of XACML into Java security architecture. In order to achieve this goal, the following aspects are taken into consideration in details. First of all, the Java security architecture and access control mechanisms are undertaken in terms of the loading of classes into Java Virtual Machine (JVM), the access control based on the code and subject, the processing of access requests. Then the syntax, the structure of XACML and its implementation are investigated. At last one proposal about the integration of XACML into Java security architecture is forwarded and then demonstrated.