Abstract: To cope with the complexity of engineering layout design,an open framework of engineering layout design CAD system is proposed.Several key methods to realize the process of computer aided engineering layout design are discussed.These include layout design process modeling,functional feature-based components and container approximate modeling,representation of layout knowledge and layout constraints and application of layout approaches.A computer aided engineering layout design system is developed to implement the framework.The system is demonstrated with a practical engineering application of a vehicle engine compartment layout design.