Current Grid Security Infrastructure using PKI based on SSO. Trust is hard to establish in a service-oriented grid architecture because of the need to support end user SSO and dynamic transient service. Open Grid Service (OGS) Security Infrastructure in Global Grid Forum will extend use of Grid system or services up to business area using XML Web Service security technology. This paper describes a novel security approach on Open Grid Service to validate certificate based on current Globus Toolkit environment using XKMS and SAML, XACML in XML Security. Our security model is based on XKMS, an implementation of the Java component and international standard specification.