Debris flow is a kind of mass movement with great destructive potential. During debris flow process, its mechanism is influenced by topography, flow condition and debris composition. This study is based on the characteristics of occurrence, flowing, and deposition of debris flow, which suggested that the potential hazardous areas for potential streams should be shown by three patterns: (a) the alluvial fans, (b) the local deposit areas, and (c) the areas influenced. By means of theoretical analysis, aero photo judgment and field investigation, the evaluation of the hazardous areas and patterns are revealed. The location of the case study is three creeks in Kuanshi, Hsinchu. As a result, the proposed methodology can clearly demarcate the potential hazardous areas of debris flow rapidly and rationally for different topographic and hydrographic characteristic of creek.