In order to study the importance of chemical component index among tobacco quality evaluation, the paper evaluated the importance of chemical components according to the relationship between chemical components and sensory quality by grey superior analysis. The results indicated that a group of chemical component index which has close connection with sensory quality had been found by grey superior analysis and tobacco chemistry analysis. For the flue-cured tobacco of Chuanyu tobacco base from the main tobacco-growing areas in north, the tobacco quality evaluation indexes were protein, pH value, citric acid, oleic acid, hexanoic acid dihydroactinidiolide, mgastigmatrienone D, phenylacetaldehyde and dihydro damascenone while the tobacco quality evaluation indexes reduced to nine from sixty-five.