Abstract: To investigate regional differences in free amino acid contents and compositions in flue-cured tobacco, and to establish the relationships between free amino acids and flavor types of flue-cured tobacco, 320 leaf samples were collected from typical tobacco-planting areas with "robust", "medium" and "fresh" flavor types. The differences in free amino acid contents and compositions between leaves from areas of different flavor types and the variability in leaves from areas of the same flavor type were analysed. A correlation model between the free amino acids and the flue-cured tobacco flavor types was established. The results showed that:1) The contents and compositions of free amino acids were significantly different in flue-cured tobacco leaves for the different flavor types. The contents of 19 free amino acids and the proportions of 13 free amino acids in samples of different flavor types were significantly different, and their variations were consistent in middle and upper tobacco leaves. 2) In tobacco-planting areas of the same flavor type, the variation coefficients of contents and proportions of free amino acids were significantly different, their average variation coefficients were 19.6%-66.2% and 8.6%-54.3%, respectively. 3) Based on the contents and compositions of free amino acids, a discriminant model for tobacco leaf flavor types was established by using a stepwise discriminant analysis. External validation (220 samples) indicated that the accuracy of the model reached 83.6%. 4) The contents and proportions of β-Ala, Ile, Gly and Tyr were found to correlate to the flavor types of flue-cured tobacco.