Baiyinhua lignite (BL) was sequentially treated in cyclohexane, CH3OH, CH3CH2OH, and (CH3)(2)CHOH at 300 degrees C to afford soluble portions (SPs) 1-4 (SP1-SP4), which were analyzed with a Fourier transform infrared spectrometer, gas chromatograph/mass spectrometer (GC/MS), and quadrupole exactive orbitrap mass spectrometer (QEOTMS) with atmosphere pressure chemical ionization source in negative-ion mode. In addition, it was characterized with a solid-state C-13 nuclear magnetic resonance and X-ray photoelectron spectrometer (XRPES). The results show that aliphatic and aromatic carbons, accounting for 37.1% and 59.2%, respectively, are dominated in BL. Each aromatic cluster contains 2 rings on average with 3 substituent groups on each ring. According to the analysis with XRPES, -OH group is the most abundant existing form of oxygen in BL. The analysis with GC/MS shows that the most abundant group components are arenols in SP1 and SP2, and alkanoates in SP3. Thousands of oxygen-containing aromatics (OCAs) were resolved with the QEOTMS and the molecular masses are mainly in the range of 250-400 mu. The main OCAs detected are O-1-O-6 class species, dominated by O-2-O-5 class species, which could be mainly assigned to acidic species, such as alkylarenediols, allcylarenetriols, and alkylarenoic acids.