Based on top of Web protocols and XML language, Web services are emerging as a framework to provide applicationto-application interaction. An important challenge is their integration in order to provide new value-added composite services, allowing consequently Business-to-Business relationships. Therefore, many composition languages have been proposed in the past few years. However, a weakness of these languages is that they are difficult to use in early stages of development, such as specification. Thus, an extension to UML 2.0, named UML-S, was introduced to develop composite Web services conforming to the modeldriven engineering vision. This paper introduces the necessary transformation rules between UML-S and low-level code to comply with MDE approach. Categories and Subject Descriptors H.3.5 [Information Storage And Retrieval]: Online Information Services--Web-based services; I.6.5 [Simulation And Modeling]: Model Development--Modeling methodologies General Terms Design, Language...