Service oriented architects (SOA) is considered as an extensible, robust and platform independent web application architect. However, problems in security guard for service access remains unresolved especially for the measurable one. we proposed a novel access control model, which we called SACM: Service Access Control Model, specially for SOA. Our model is mainly based on the role access policy, extended with trust authority transition and integration mechanism, to fulfill an extensive and measurable access control modeling approach with Crypto-CCS.