Abstract: The gas coal and the coking coal were extracted with tetrahydrofuran（THF） solvent at 50 ℃ and atmospheric pressure by microwave-assisted extraction. The experiments using forward penetration method and low-temperature nitrogen adsorption method to carry out wettability test and pore structure for raw coal and their residues were carried out． The results indicate that the total pore volume increases after extraction and the soluble organic matter is dissolved, which plays a role of reaming and increasing pores. However, due to the different occurrence characteristics of dissolved soluble organic matter, gas coal is mainly for reaming pore and coking coal is mainly for increasing pore; the wettability of coal is significantly lower after extracting, gas coal in particular, the wetting height is more than twice of the residual coal at the same raw coal wetting time. The analysis suggests that the coal microcosmic pore structure is changed after the soluble organic matter dissolved, the methyl, carbonyl and other groups on the coal surface are reduced, and then the coals’ wettability is decreased.