中文摘要：

介绍了在企业信息化发展的过程中，企业门户的应用背景、特点以及普遍采取的三种访问控制方法。讨论了SharePoint门户的体系结构和基于角色的访问控制体系，并在此基础上讨论了基于SharePoint门户的体系结构对RBAC方法的扩展应用．以及该体系结构所采用的层级继承和安全策略。将SharePoint中的RBAC体系与WindowsServer2003操作系统的NTFS权限进行了比较，指出了其中的优点和不足。通过将WindowsServer2003操作系统的活动目录与Share—Point中的RBAC体系进行结合，提供一个更为安全的企业门户平台。

英文摘要：

Introduce the application background of enterprise portal and the access control methods adopted during the process of the enterprise information development. Then architecture of SharePoint portal and the RBAC systems adopted by SharePoint is discussed in detail, and then talk about the hierarchy- inherit and the security strategy. At last,compare the RBAC systems in SharePoint portal with NTFS rights system in Windows Server 2003 OS, and then point out the advantage and shortage of the RBAC systems in SharePoint portel. Through combining the active directory with RBAC systems in Share.Point, can provide a safe enterprise portal platform.