Sorption of various organic vapors by Argonne Premium coals (APCS-1, 3, 5, and 8) was investigated to clarify the coal-organic interaction, sorption mechanism, and micropore and crosslinking structure of coals. Especially, the sorption at low vapor pressures could be measured under a temperature- and pressure-controlled gravimetric sorption system. Methanol was quickly sorbed by all the coals used. In contrast, pyridine was slowly sorbed by Beulah-Zap lignite coal, and a significant portion of pyridine was retained after desorption. The quantity of methanol sorption at saturation vapor pressure (P/P-0) at 30 degrees C showed a good correlation with oxygen % (daf) in the raw coals, indicating that methanol is sorbed by the coals through interaction with oxygen functional sites. For high-rank Pocahontas No. 3 and Upper Freeport coals, the methanol isotherm could be explained by the both Langmuir-Henry and Dubinin-Radushkevitch-Henry dual-mode sorption equations, while for the other coals the Langmuir-Henry equation was better for the approximation. For Illinois No. 6 coal, at relative vapor pressures of 0.01-0.7, the sorption could be treated by the Langmuir-Henry equation regardless of the kinds of organic vapors (methanol, benzene, pyridine, and cyclohexane). For Beulah-Zap coal, the sorptions of benzene and cyclohexane were significantly small due to their small interactions with the coal surface, resulting in either dual-mode equation being inadequate. In contrast, for high-rank coals (Upper Freeport and Pocahontas No. 3) benzene or pyridine sorption isotherms could not be determined due to their slow sorption.