The relativity analysis between water level and barometric pressure in Dadianzi well, Chifeng city, Inner Mongolia, is done, and the Barometric pressure coefficient background value of this well is obtained. Meanwhile the varieties of the well＇s Barometric pressure coefficient before some moderate-strong earthquakes in the east of Inner Mongolia are analyzed, and the result shows that high value ＆ low value variation of the coefficient reflects possibly characteristic of earthquake precursor.