Abstract: By analyzing the information of Gaoda well since2002,analyzing the water level variation over the years and the abnormal morphology before the M5 earthquake around the observation well within the range of 300km,we found that Gaoda water level shows trend and short term variation characteristics before the earthquake,and it has a good corresponding relationship between the dynamic anomaly in water level and the M5 earthquake around the observation well within the range of 300 km.