Abstract: In order to reveal the structure and properties of tobacco starch and reduce its content in flue-cured tobacco leaf, the extraction conditions of starch from fresh leaves were optimized with response surface methodology(RSM). The results showed that the optimal extraction conditions were the concentration of sulfurous acid 0.19%,extraction time 16 hours,and ratio of liquid to solid 7. The contents of lipid,protein and ash in the extracted starch were 0.61%,3.73% and 1.59%,respectively;and the ratio of amylose and amylopectin was 3:7.