To improve the accuracy of precipitation observations, a statistical analysis of precipitation data obtained by 38 weighing gauges in Beijing is made. The abnormal precipitation records are divided into four categories: power interference, temperaturesensitive, lag, and thawing. According to the causes and features of the four kinds of records, the corresponding suggestions are proposed, such as installing a DC manostat into the power supply, strengthening the verification of temperature coefficient, improving the structure or processing craft of weighing gauges, standardizing the maintenance operations, etc.