Abstract: Impurities in tobacco leaves purchased by X companies from 2005 to 2011 were measured in a selection workshop and their origin was analyzed. The results showed that the impurities were largely synthesized substance, indicating that the impurities came mainly from post harvest processes. Impurities in the lower leaves of tobacco were significantly higher than the upper leaves because of the inclusion of impurities from the ground at harvest. Careful harvest could thus decrease the impurities in tobacco leaves. Canvas packing could prevent effectively against impurity entrance into tobacco leaves whereby to decrease impurities compared to linen packing. It was worth noticing that impurities in tobacco leaves decreased greatly in recent years, which indicates obvious improvement of quality control and management of both farmers and managers.