Abstract:The professional connotation of particle size metrology was introduced,its basic characteristics were summaried.The features of its professional attributes and technical characteristics were analyzed,its management features were described.The different functional properties of the particle size metrology were analyzed to reflect its fundamental key role.The professional range covered by particle size metrology was defined based on systematic analysis of main characteristics of particle size metrology from different angles.The important roles of the particle size metrology played in national economic and national defense construction were clarified which contributed to comprehensive and correct understandings of characteristics,effects and contributions of particle size metrology.