Abstract: Zhundong subbituminous coal was exhaustively extracted with isometric carbon disulfide (CDS) and acetone mixed solvent. The extract was fractionated with petroleum ether (PE) and CDS into PE-extractable portion (E₁) and CDS-extractable portion (E₂). E₂ was sequentially eluted with PE and 30% CDS/PE mixed solvent through a silica gel-packed column. A series of long-chain normal alkanals (LCNAs, C_18~27) were enriched from E₂ and identified with a gas chromatography/mass spectrometer. The fractional extraction and subsequent column chromatography provide an effective approach for enriching LCNAs from middle-and low-rank coals. LCNAs could be a class of important biomarkers.