Effects of different fan speed changes on the contents of neutral aroma constituents in flue-cured tobacco leaves during bulk curing period were studied by applying frequency conversion technology. The results showed that total contents of neutral aroma components were higher under the 1 450 r/min of rotation speed than those under the 960 r/min of rotation speed when the temperature was between 42 ℃ and 54 ℃. While they reached the highest under the 1450 r/min of rotation speed when the temperature was between 42 ℃ and 54 ℃ and 720 r/min afterward; in the meanwhile, the contents of carotenoids, aroma aminophenol, maillard reaction products, cemdrenoid and neophytadiene were all higer than those under the 1 450 r/min of rotation speed during the whole process.