Abstract: The pyridine adsorption and swelling behaviors of WK11 model compound, ND and IL coals in pyridine containing water, cyclohexane and toluene binary solvent mixtures were investigated. The results suggested that the pyridine adsorption amount and swelling ratio were very low when a small amount of pyridine existed in solutions. The small amount of pyridine could not be totally adsorbed by coal even after very long experiment time. Although pyridine could break all hydrogen bonds in coal due to the more favorable entropy change, other factors including environmental surrounding solvent, pore structure of absorbent and molecular diameter of absorbate could influence the adsorption behaviors greatly. The coal swelling ratio also did not have linear relationship with the uptake of pyridine in low concentration stage. At high pyridine concentration, the swelling ratio increased with the pyridine concentration. However, the boundary between coal particles and solvents would disappear when the pyridine concentration was high enough.