Abstract: A method for determining the nitrobenzene in mainstream cigarette smoke by extraction with cyclohexane,cleanup with silica solid phase extraction cartridge,and separation by GC with the heart-cutting two-dimensional columns was developed.The deliveries of nitrobenzene in mainstream smoke of six cigarette samples were tested with the developed method,the results showed that:1) the separating capacity of chromatography was effectively improved by heart-cutting technique,it allowed the trace nitrobenzene be separated from the complex cigarette smoke matrix,and the separating efficiency was obviously better than that of GC with single-dimensional column;2) the recovery of nitrobenzene was 87.6% with relative standard deviation(RSD) of 6.82% and detection limit of 1.28 ng/mL;3) the deliveries of nitrobenzene in mainstream smoke of the test samples ranged from 0.091 to 1.66 ng/cig.