In order to better apply the mediumrange forecast products of the T639 model， s ome synoptic verification from March to May 2009 are made in comparison with ECM WF and Japan models. The result shows that three models all have good forecastin g performanes. Comparably, the ECMWF is better than T639 and Japan models in forecasting the evolution and modification of the atmosphere circulation in middle and highlatitude, and the trend of temperature in 850hPa. Taking the sandstorm process during the period of 23-25th in April as a case, T639 mo del can predict well in aspect of forcecasting surface strong wind in the proces s of the sandstorm compared with Japan and ECMWF models.