Research conclusions: The risk identification of subgrade project should be done from a specific engineering combining risk events with risk sources． The risk events must be found by the procedure of the project – sub item – branch item –construction process，as well as the risk sources at the same time from five aspects: the nature，geology，environment，design and construction，materials． The treatment of risk shall comply with the following basic principles: using the economic and reasonable technical and control measures to prevent the subgrade risks，lessening or reducing loss caused by risks and avoiding collapse，sliding，which is difficult to restore and affects normal function． subgrade risk should be controlled from its root． In the planning and design stage，the identified risk that is likely to cause the delay of schedule or cause heavy loss should be remedied by adjusting line plane or profile，adopting substitute program or other optimizing program to avert or reduce risks． Economic and rational technical measures are needed to guard against the risks in subgrade projects．