Basic nitrogen compounds in coal liquefaction oil were extracted by acid extraction method and analyzed by gas chromatography-mass spectrometry（GC-MS）and gas chromatography-nitrogen chemiluminescence detection（GC-NCD）.It can be seen from the analysis that basic nitrogen compounds were clean separated out from the oil sample through acid extraction.38 kinds of basic nitrogen compounds in the full range of coal liquefied oil were determined by GC-MS,and they were mostly pyridine class,aniline class and quinoline class.18 kinds of basic nitrogen compounds were quantified by GC/NCD and the content accounted for 88.9% of total basic nitrogen compounds,in which the pyridine class accounted for 24.48% of total basic nitrogen compounds,aniline class accounted for 37.98%,and quinoline class accounted for 26.48%.