Abstract: Industry Foundation Classes (IFC) has been known as an international common product model for Building Information Model (BIM) exchange and sharing in building field. With the purpose of solving the problem of model sharing between structural design and other application followed, the IFC is introduced into the structural working drawing field. Combining the demand for data description, an IFC extension model was established through entity extension and property extension. The extension model was verified by BIM-based structural drawing design prototype system in a test project. The research shows that extended IFCs is suitable for BIM model description in structural working drawing. Automatic model exchange is realized between structural working drawing and quantity survey by the extended IFCs.