Abstract: The present paper experimentally and theoretically investigated the coal particle surfaee in combustion,The measurement system composed of an ESM and an image computer was developed and used.The particle surfaces were measured with the system for various kinds of coal in different burning ways. Based on the experiment,the particle surface smooth factor theory of coal combustion was put forward, The relationship between coal combustion and the particle surface smooth factor was established in the theory,The effects of combustion on the particle surface were discussed.

Key words: coal combustion, particle surface, image computer, smooth factor, energy pattern