In recent years, more frequent extreme rainfall events have led to the uneven temporal-spatial rainfall distribution, which had resulted in the dramatic variations in rainfall intensity, rainfall frequency, and rainfall duration. After the 921 Earthquake in 1999, the hillside soils of Taiwan have been severely loosened. Any typhoon rainfall could triggering debris flows possibly. Therefore, the data of typhoon rainfall observed at 141 rainfall stations in the central region of Taiwan have been used in the hydrologic frequency analysis (according to the rainfall intensity of each typhoon event). Five analysis methods are adopted for this research, namely Normal Distribution, Logarithmic Normal Distribution, Extreme-Value TypeⅠDistribution, Pearson TypeⅢ Distribution, and Log-Pearson TypeⅢ Distribution. This research also plotting the isohyetal rainfall of debris flow-prone streams and return periods of rainfall duration in each area in central Taiwan. The influence of typhoon rainfall over the central region of Taiwan is analyzed in this research as well.