Abstract:Abstract: The automatic weather station was established in 1999 in the station. The AMS-II automatic meteorological observing system developed by Institute of Changchun Meteorology was used. Precipitation data was logged and recorded by using tipping bucket rain gauge telemetry. Due to the closure data logger, error operation, log rainfall data, the flaws of software design, interference pulse for rain sensor, dump wrong turning, solid precipitation etc. reasons, the rainfall data and recording appear abnormal. The paper analyzed the situation and the problem about rainfall data abnormal of automatic weather station.