Abstract: Nine chemical indexes of 195 samples of Hongda tobacco leaves harvested in 2010 from 13 counties of Liangshan in Sichuan Province were determined, the usability indexes of the chemical components were calculated with membership function method, and the usability of chemical components of those samples was comprehensively evaluated. The results showed that:1) The contents of total sugar and reducing sugar and the ratio of sugar/alkali in the samples were relatively higher, while the potassium content was relatively lower, chlorine content was lower and with larger variation, however, the other chemical components and ratios were all within proper ranges. 2) The contents and ratios of chemical components differed significantly between the samples from different counties. 3) The usability indexes of chemical components in the samples from different counties differed obviously.