Abstract: To improve the security capability for gird portal that is accessed by ordinary users jobs and to guarantee that portal have a secure access to gird resource is very important.According to the feature of grid portal, we design and analyze a safe portal mechanism with Globus Toolkit middleware technology to implement an architecture.We achieve both a credential processing architecture and gird portal credential security architecture.The experiment result shows that through this kind of design and analysis of gird portal, we could protect the safety of grid portal itself well.In addition, this architecture would ensure that every grid computing resource that is accessed by portal through grid can be safe as well.