Tremendous landslides and collapses caused by intense earthquake usually induce numerous debris flows in rainy season. This study explores to make a quick assessment of frequency, magnitude, and danger of debris flow by a case study of the Yingxiu - Chediguan section of G213 highway hit by the Wenchuan earthquake. Key factors influencing the formation, magnitude, and frequency of debris flow are chosen and numerically determined through interpretation of remote sensing images and related DEM maps. The values are divided into five grades and normalized between 0 and 1. The weight for each factor is calculated by hierarchy analysis. Finally, the universal model is used to assess debris flows in 21 gullies. Comparison with the real occurrences indicates the assessment re- suits are in good agreement. The assessment system can be further applied to debris flows in other regions of high- intensity earthquake.