Abstract: In order to investigate the variation in size distribution of cut tobacco in the process of transportation and the effects of size distribution pattern of cut tobacco in tobacco rod on the stability of cigarette physical indexes,finished cigarettes and the cut tobacco in silo,maker's hopper and garniture were sampled as a group,the physical indexes of 22 groups of samples were determined and analyzed with gray incidence analysis method.The results showed that:there existed close correlation between the size distribution profile of and moisture content in cut tobacco in tobacco rod and the stability of cigarette quality;nevertheless,the effects of different size portions were varied,the percentages of cut tobacco from 2.50 to 3.35 mm in length or longer obviously affected cigarette weight,draw resistance and dust content.In the process from silo to garniture,the change of any size portion in one step would bring about the changes of one or more size portions at next step.