Abstract: Based on the measured tidal data in Hangzhou Bay，the spatiotemporal variations，causes and influencing factors of the annual maximum high tide levels in Hangzhou Bay were systematically analyzed. The results showed that the annual maximum high tide levels in Hangzhou Bay rose in a fluctuating manner，with a rising rate of 0.951.84 cm/a，the raise valuetop of the bay was larger than the middle of the bay and the middle of the bay was larger than the mouth of the bay. The annual maximum high tide levels occurred most frequently in August，followed by July，September and June. In the annual maximum high tide levels at Zhapu station，59% of them were affected by typhoon surge，and 95% of them were in spring tides. On the，contracted river for regulation in the Qiantang estuary caused the elevation of the high tide level of astronomical tide，on the other hand，it caused the increase of storm surge. In the past 30 years，the increase of typhoon intensity and adverse typhoon path for Hangzhou Bay also caused the increase of storm surge and the elevation of the annual maximum tide level iu Bay was exacerbated by rising mean sea level.