Huyu Valley is located in the Xishan area of Taiyuan City,Shanxi Province.The occurrence of debris flows in the valley directly threatens the security of the local people.To further identify the hazards of debris flows in the area,the geologic processes are studied through the investigation of potential debris flows in the valley,including tectonic activities in Xishan area,complex topography and geology formed from stream incision,loose deposit caused by natural weathering and human activities,and unbalanced distribution of rainstorms.A analytical approach to risk assessment is used to analyze debris flows in the valley.Results indicate that the risk degree of debris flows in the valley is 0.768,being a highly dangerous degree,and they may threaten the downstream if erupting.