As Internet enhancing its distributed computing characters, Web Services have gained great development and multi-domain environment application becomes more and more popular. But across different domains, the traditional RBAC model is facing some troublesome questions, such as user-role assignment and mapping difficulty. Web Services access control model based on attributes in multi-domain environment is presented. Attributes, extending from roles, can make up those shortcomings of RBAC, and also make access control more flexible, dynamic and fine-grained. Meta-attribute and meta-policy are presented to describe the attributes and policies in local domains.