Abstract: Using topographic maps, attribute data of watershed and outputs of flash flood disaster investigations, this paper presented the techniques and outcomes for flash food disasters assessment in Yuzhou District. The primary preparedness for assessment was firstly introduced. Then, it was demonstrated that the major components of assessment, including design rainfall-runoff determination in watersheds, existing flood conveying capacity estimation, critical rainfall and stages determination, and flood hazard mapping for the villages along streams in mountain-hill-area in Yuzhou District. Finally, recommendations were provided to assist flash flood prevention and control in Yuzhou District, improving the monitoring and earning warning system on flash flood, and identifying potential flash flood types and areas.