Abstract: A systematic method is presented to transform EXPRESS models into various target models. The resultant system contains a model-independent layer, a partially and a fully model-dependent layer, respectively processing the information flow in different stages of model transformation. Some key techniques in the conversion of EXPRESS schema, including the presentation of inheritance hierarchy and EXPRESS constraints in some typical types of data models, are also introduced. With such a method, the transformation to a specified target model can be categorized into a well-known type and be implemented within an existing framework. This improves the consistency of target models, as well as the extensibility of the model transformation system.