Neutral fraction of cigarette particulate matter was investigated by comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometric(GC×GC-TOF MS) method.An HP-5MS(50 m×0.2 mm i.d.×0.33 μm) column was chosen as the first dimensional column and a DB-17MS(1.7 m×0.1 mm i.d.×0.1 μm) as the second dimensional column to separate and analyze the neutral constituents of smoke particulate matter of high-quality tobacco.Total of 1 464 compounds were tentatively identified by TOF MS software based on auto data processing combined with manual data processing.The structured related compounds such as ketones and aldehydes eluted in bands or clusters in the GC×GC chromatograph were investigated.The retention time for 36 flavor constituents in the first dimension and second dimension were discussed,and the characteristics of the aldehydes in the comprehensive two-dimensional gas chromatography were studied. The information and the interpretations of spectra characteristics will enhance the reliability of compound identification and be helpful in the study of tobacco smoke and other complex system.