To study the variation characteristics of the annual maximum high tide level at the Nanjing Station, the comprehensive diagnosis method was used to analyze the variation tendency of the annual maximum high tide level, dbN series wavelet and Complex Morlet wavelet were employed to carry out wavelet analysis for the anomaly series. The results show that there is no significant variation tendency for the general series of the annual maximum high tide level at the Nanjing Station, but significant local tendency was found; four main variation periods for time scale of 5, 11, 40 and 63 years were found with Wavelet analysis. The analysis may be helpful to some extent for realization of the changing pattern of the tide level at the Nanjing Station, local water security and reasonable development of water resources.