In this work, pectinesterase, pectinlyase, polygalacturonase and cellulose-preparation enzyme were used to decompose cell wall substances of flue-cured tobacco, and the contents and structure of the pectin in tobacco and the changes of the ratios of neutral sugar in pectin were investigated. The result showed that the 4 enzymes could decompose cell wall substances in tobacco effectively, and cell wall substances were decreased with the highest decrease of 17.8%. The degree of methylation in pectin was decreased evidently in tobacco treated with pectinesterase and pectinlyase while increased slightly in tobacco treated with polygalacturonase. The contents of neutral sugar in pectin increased in tobacco treated with the 4 enzymes, but there were much difference in the ratios of neutral sugar with different enzymes. The total contents of flavor components (without neophytadiene) in tobacco treated with pectinlyase and polygalacturonase were increased by 24.4% and 21.9%, respectively.