The Industry Foundation Classes(IFC) developed by International Alliance for Interoperability(IAI) has been known as a common product model for data exchange and model sharing.In architecture design, entity types and property sets in IFCs are nearly enough to meet the needs.However, in the construction, entity types are insufficient for data description.Therefore, we analyses the demand for data description in construction in mainland China, and extend the IFC model.At last, we test the extension model by some real projects and give some suggestions for further research.