Observation data of water tube tiltmeter with type FSQ of Tanchang station from 1990 to 1998 are analysed. The results show that observing accuracy of tide response function is in the observation standard. Influence of hydrologic and meteorological factors on observation data is obvious. Short-imminent anomalies in a certain ex tent in the observation data of Tanchang station appear before earthquakes with magnitude of 4 or so in the vicinity of the station and trend anomalies appear before mid-strong earthquakes within a distance from the station.