Abstract:  Three coals were combusted in a drop tube furnace. An Andersen particle sizing impactor was employed to separate and collect the ash particulate matter (PM) after coal combustion. Mercury injection apparatus, SEM-EDX, ICP-AES were taken to detect the tested coals and graded ash PM. The effect of coal physicochemical properties on ash particle size distribution (PSD), appearance, constituents and enrichment of trace elements of PM was examined. The results show that the pore structure of coals, occurrence characteristics and concentration of constituents influence the behavior of ash fragmentation and the transition procedure of constituents, forming different morphological and inequable PM, and leading to the different PSD. Simultaneously, they will influence the vaporization and coagulation of elements as well as the redistribution in the graded PM.