Combustion of super fine particles is a new pulverized coal combustion technique. Compared with conventional combustion techniques, it has the advantages of good flame stability, high burnout, low NOx release, and low comprehensive cost. Using NETZSCH thermobalance, STA 409C, and maintaining the test conditions for all the samples at the heating rate of 20 degreesC/min, the paper investigated the combustion properties of Heshan (Hs) subbituminous coal and Jincheng (Jc) lean coal, each in four different average sizes. Significant improvement of combustion properties was observed when particle size was reduced down to 0-20 mum.