Abstract: Miero fluctuations related to the stress-strain change in rocks holding water are studied by use of such method,other than the dynamical approach,as the Pertsev's filter to resolving long/short-term variations of water level and regression analysis to eliminating and analyzing the correlation factors affecting the water level.The compromise analysis is applied to the analysis of earth tide of water level.The multichannel welner filtering is used for comprehensive predicting the fluctuations of ground water level and searching out the abnormal time-interval prior to an earthquake.At last,the observed data of water level from the well at Ta-Yuan in Beijing are of practical significance in providing the information about seismic indications and in distinguishing anomalies in water level from the normal fluctuations.