Structure and methods of the objective verification system on operational numerical weather forecasting in Beijing area are introduced in detail. On the base of the analyses on verification results of main forecasting products in the winter of 2001 (from 1st Nov. 2001 to 28th Feb. 2002), the characteristics of error distribution of operational numerical forecast in Beijing area are shown. In addition, the systematic and non systematic errors' possible sources in operational numerical forecast are analyzed....