Abstract: The stock- tobacco grade quality was analyzed using sampling data from supervision of grade quality of countrywide flue- cured tobaccos during business- deal period in 2005. The results indicated that the grade quality of stock- tobacco in a corporation governed the qualification rate of the leaf grade of the industry- commerce deal, although there was significant difference of the tobacco grade quality among various enterprises. Analysis of the component of the origin grades illustrated that a main problem of the low qualified rate of the stock- tobacco was a widespread existence of the mutual confusion of leaves among positions from the plant, among colors, and among grades. In origin grade, the proportion of the mixed low- quality- grade leaves was far higher than that of the high- quality- grade leaves mixed. Moreover, the eligible percentage of the tobacco grade was low for leaf grades with large purchase quantity or high price, while the qualification rate of leaves from the middle portion of the plant was quite lower than that of the tobacco from the upper and lower portion. Some suggestions were made for improving grade quality of tobacco.