Abstract: The step changes of Huanghua well water level since 2007 are studied and their normal amplitude are calculated through solid tidal stress analysis,and then the standard of the Huanghua well level step change is set on basis of the result. According to this standard, the daily frequency, the monthly frequency and the amplitude of the Huanghua well level step change are summarized and its characteristics are studied combined with seismic activity of Tanlu seismic belt. The results show that there is a certain relationship between the step change of water level of Huanghua well and the seismic activity of Tanlu seismic belt:the seismic activity of the Tanlu seismic belt is more active during the higher frequency and the higher step change amplitude, however, the corresponding rate of single step change and single earthquake is lower. The results may provide some basis for the prediction of earthquake in the eastern region.