Shengli lignite was subjected to thermal dissolution in a methanol/benzene mixed solvent at 240 degrees C for 1 h. The soluble fraction was sequentially eluted with petroleum ether and 5, 10, and 15% carbon disulfide/petroleum ether mixed solvents through a silica gel-packed column to afford eluted fractions 1 to 4 (EF1 to EF4). In total, 15 methyl alkanones from C-15 to C-27, including 2 methyl side-chain alkanones and 13 methyl straight-chain alkanones were enriched in EF4 and identified with gas chromatography/mass spectrometry.