Abstract: In order to study the yellowing characteristics of different tobacco varieties and predict the changes of chlorophyll content during the yellowing stage. Changes of flue-cured tobacco leaves' chlorophyll content in different varieties (Honghuadajinyuan, K326, Yunyan85) under different yellowing temperature (34℃, 36℃, 38℃, 40℃ and 42℃) were analyzed, and the degradation kinetic model of flue-cured tobacco leaves' chlorophyll was established. The results showed that flue-cured tobacco leaves' chlorophyll content got a faster degradation with the increase of yellowing temperature. There was a lag phase of flue-cured tobacco leaves' chlorophyll degradation at the low yellowing temperature (such as 34℃ and 36℃), however, there was no lag phase at the high yellowing temperature (such as 40℃ and 42℃). The chlorophyll degradation of the Yunyan-85 variety was the fastest, followed by the variety of K326, and the variety of Honghuadajinyuan got the slowest degradation. The first-order reaction kinetic model can well describe the variation of flue-cured tobacco leaves' chlorophyll content during the yellowing stage. The half-life(t_1/2) of flue-cured tobacco leaves' chlorophyll degradation was shortened with yellowing temperature increased. The chlorophyll degradation activation energy of the varieties of Honghuadajinyuan, K326 and Yunyan85 leaf were 61.76, 56.20 and 53.16 kJ/mol respectively. The chlorophyll degradation reaction model based on the variation of temperature fluctuation was established in the test, which could provide a theoretical reference for the accurate prediction of the changes of chlorophyll content in tobacco leaves during the yellowing stage.