To improve the interior and exterior quality of NC297 and NC102, the dry- bulb and wet- bulb temperature were controlled during yellowing period, taking lower, lumbar and upper leaves as experimental materials. Lower and middle leaves of NC297, when the dry-bulb temperature and psychrometric difference were 38℃and 2- 3℃respectively in yellowing period, the appearance quality and economic characters of tobacco leaves were better, their chemical compositions tended to be coordinative. About upper leaves of NC297, when the dry-bulb temperature and psychrometric difference were 36℃and 2-3℃respectively in yellowing period, the appearance quality and economic characters of tobacco leaves were better, their chemical compositions tended to be coordinative. For lower leaves of NC102, when the treatment that the dry- bulb temperature and psychrometric difference were 40℃and 2-3℃, the economic characters and exterior quality were better, as well as the harmoniousness among different chemical composition. The middle leaves of NC102, when the dry- bulb temperature and psychrometric difference were 38℃and 2- 3℃, economic characters, exterior quality, were better. About upper leaves of NC102, when the treatment that the dry-bulb temperature and psychrometric difference were 36℃and 2-3℃, economic characters, exterior quality, were better. To flue-cured leaves of tobacco of NC297, lower and lumbar leaves, the yellowing temperature should be controlled at 38℃, upper leaves at 36℃. About flue cured tobacco of NC102, the lower leaves, yellowing temperature should be controlled at 36℃, lumbar and upper leaves should be controlled at 38℃and 36℃.