Abstract: In order to clarify the mechanisms behind the contents of glucose, free amino acids and Amadori compounds in tobacco leaves and their correlations during flue-curing, the variations of these compounds in middle leaves of K326 and Bina 1 before and after curing were analyzed by adopting the half-leaf sampling. The conversion rates of six free amino acids to Amadori compounds and their differences between the two cultivars?were compared.?The results showed that: 1) The total amounts of glucose and free amino acids of the two cultivars increased significantly after flue-curing. The increase of the total amount of free amino acids was mainly due to the substantial increase in the content of proline, the contents of different amino acids varied greatly with different change trends.?Six Amadori compounds formed during flue-curing, and the variation trends of their contents were consistent with the overall trend of?free amino acid contents in the flue-cured tobacco leaves. The content of Amadori compound converted from alanine was the highest, followed by proline, and that from leucine was the lowest. 2)The conversion rates of different free amino acids to Amadori compounds differed significantly in the flue-cured tobacco leaves: alanine was the highest, valine was the second and proline was the lowest.?There were also significant differences between the two cultivars: the conversion rates of five free amino acids (alanine, proline, valine, leucine and tryptophan) in Bina 1 were significantly higher than those in K326.?Thus it could be seen that the contents of Amadori compounds in the flue-cured tobacco leaves were affected by the contents of free amino acids and the Maillard reaction activity, and the differences of the hereditary characters between the cultivars also affected the conversion of the Maillard reactions and the contents of Amadori compounds in the two types of flue-cured tobacco leaves.