Abstract: TCM-90 data and numerical simulation were used to study the feature chandges of Typhoon Dot encountering Taiwan,including the formation of secondary centers of circulation and geopotential fields,the combination of main centers with secondary centers,the abruptly change of tracks in combination of circulation centers,the abnormal northward movement of the low in west edge of Taiwan,and the strait jei,etc.3-hour simulation results were analysed which is imposible to have in the observation.Finally,the mechanisms of the feature changes were investigated through control experiments.