The widely used rain gauges at present include basically telemetering rainfall sensors for automatic weather stations， doubleskip telemetering raingauges， siphonage raingauges， common raingauges and so on. By means of the rainfall data in recent years from Chaoyang Station of Beijing， the causes of errors in the measurements of various raingauges under different rainfall conditions are analyzed. It is found out that although the working principles of the instruments are about the same， the performance may be different obviously because of their capability differences and unpredictable breakdowns. As the rainfall intensity may vary suddenly， it is inevitable for raingauges to produce measuring errors. Some suggestions are proposed， which can provide reference for precipitation metrical data analysis.