Abstract: The content of leaf protein and the composition of amino acids in major varieties of flue-cured tobaccos such as G28, 91 -5, NC82, K326, Qiansuo No. 2, 8611, and Hongda No. 12 in Sichuan province were analy zed. And the essential amino acids (EAA), semi-essential amino acid (SEAA)and amino acid score (AAS)in each tested tobacco leaf were compared. The results showed that the Hongda No. 12 had higher protein and lower ESS, SEAA, and ASS, so it's nutrition value was lower than that of NC82 which had lower protein content. Higher le af protein contents in these tested flue-cured tobacco 7 varieties than those in corn and sesame were also found. It was concluded that the leaf protein in flue-cured tobacco was a sort of high quality protein source.