Abstract: The relationship between free amino acids and sensory quality of Hongda C3F flue-cured tobacco leaves from Kunming was studied by partial correlation analysis and canonical correlation ana1ysis. The correlation between them was significant. Among them, arginine, methionine and tyrosine were found to active to the sensory properties, and valine was negative based on partial correlation analysis. Arginine, methionine, tyrosine, glycine were revealed contributing to the canonical correlation between free amino acids and sensory properties, including concentration, aroma volume, smoke strength, abundant, sweetness, offensive taste and irritancy. Increasing content of arginine, methionine, tyrosine, glycine, isoleucine within moderate range could improve the sensory properties but negative when they were beyond the limit.