Abstract: Bemisia tabaci MED has been an important pest insect in tobacco production in China in recent years.To understand the resistance of different tobacco cultivars to B.tabaci MED, we compared the performance of whiteflies on seedlings of 6 widely cultivated tobacco cultivars by using clip-cages in this study.The results showed that longevity, fecundity, survival and development time, but not hatch ratios of eggs of B.tabaci MED differed significantly on different tobacco cultivars.The highest longevity of whitefly males was found on K326 with 7.2 days, and the lowest was found on Yunyan 87 with 1.8 days.For females, the highest longevity was found on Cuibi 1 with 35.9 days, and the lowest was found on NC89 with 9.6 days.The highest and lowest fecundity were observed on Cuibi 1(236.5 eggs per female) and NC89(27.8 eggs per female), respectively.Whiteflies developed the fastest on Honghuadajinyuan (19.5 d) but the slowest on Yunyan 99(21.1 d).The highest and lowest survival rates were found on Honghuadajinyuan (91.6%) and Yunyan 99(81.4%), respectively.In conclusion, fitness of B.tabaci MED on different tobacco cultivars ranked as Cuibi 1 and K326 > Honghuadajinyuan > Yunyan 99 and Yunyan 87 > NC89.