Abstract: The liquid bridging force induced by surface moisture of wet fine coal is the main factor leading to agglomeration of particles, and the desorption work of fine particles is related to moisture content and size of particles. In order to explore the influence on air classification of wet fine coal with different contents of surface moisture, semi-industrial test is made with the small anthracite of Chengjiao Mine of Henan Coal Co. Ltd using a new type of dry classification system. Test result shows that classification size and efficiency tend to decrease all with the increase of moisture content; the system can work with an actual classification size up to 3 mm and the system is suitable for carrying out presizing of high-ash power coal or fine sizing of bunkered wet cleaned products.