Abstract: Based on the concept of the moment method, the poly-dispersed particulate matter (PM) generated during pulverized coal combustion was partitioned into fine-mode and coarse-mode. A set of computation models for describing the behavior of particle size distribution (PSD) evolution was then developed, which considered the effects of the Brownian coagulation of fine-mode, the heterogeneous condensation on the surface of coarse-mode.The influence of capture of fine-mode particles on the surface of coarse-mode particles was specially investigated.The models were then used to make prediction and analysis of the PSD evolution of fine PM in typical coal combustion environment.