The recycled oil from coal liquefaction was separated into three fractions(saturates,aromatics and polar fraction) by liquid chromatograph according to group composition.Each fraction was analyzed qualitatively by 1H-NMR spectra,then the aromatic fraction was characterized using gas chromatograph/mass spectrometer(GC-MS).It shows that liquid chromatograph is well used to separate coal liquefaction oil with high repeatability and high recovery yield.Aromatic fraction with carbon number from C10 to C21 mainly includes dicyclic-,tricyclic-and tetracyclic-hydrogenation aromatic compounds such as tetrahydronaphthalene,hydrophenanthrene,hydropyrene and their alkyl substitution compounds and so on.