This paper presents a flexible service-oriented architecture for cross-enterprise business integration and cooperation, which is based on the dynamic composition of the cross-enterprise Web services. The developing and deploying of Web services are fully separated to achieve the dynamic deploying of the Web services on the cross-enterprise servers. During the process of dynamic service composition, services discovery, negotiation and binding will be executed dynamically to address the flexibility under the service-oriented architecture. Furthermore, an efficient mechanism of trusted right delegation is also presented to address the security on sharing of the cross-enterprise resources among the Web services.