Abstract: The correlation between main chemical components and sensory quality of flue-cured tobacco was analyzed by grey incidence analysis proposed in grey system theory.The results showed that there's clear negative correlation between the chemical components such as protein, total nitrogen and nicotine etc., and the sensory quality such as quality and concentration of aroma, offensive taste, irritancy, after taste and so on, but these chemical components and the sensory quality such as physiological strength and taste strength were clear positive correlation. The chemical indexes, for example, ratio of sugar and nicotine and total sugar, and the sensory quality such as quality of aroma, concentration of aroma, offensive taste, irritancy and after taste etc., were clear positive correlation, but this chemical indexes and the sensory quality such as physiological strength and taste strength were clear negative correlation.In the past, the concept of the quality indexes of flue-cured tobacco, for example, ratio of sugar and nicotine, was not overall, so it should be amended.Total nitrogen and nicotine were more important chemical indexes, the effect of total nitrogen on concentration of aroma was clearer, but the effect of nicotine on physiological strength was the clearest.Application of grey incidence analysis in tobacco quality evaluation is more effective.