The first satellite of the National Polarorbiting Operational Environmental Satellite System (NPOESS) will be launched in 2010, and the Visible/Infrared Imager/Radiometer Suite (VIIRS) is the primary instrument in the NPOESS series. Its expected imagery is the first userrequirement product. A brief introduction is made to the characteristics of VIIRS instrument. By means of the imagery products in the similar channels of other sensors aboard in the satellite systems in existence, the concise analysis of VIIRS’s cloud imagery products is given on the basis of physical principles of cloud explanation. The application of VIIRS imagery will allow analysts to distinguish more readily the difference between clouds and cloudfree surfaces, and it will significantly improve the performance of cloud analysis and weather forecast.