Abstract: In order to investigate the effects of altitude on the quality of flue-cured tobacco leaf, the contents of petroleum ether extract, total nicotine, reducing sugar, total nitrogen, chlorine and potassium in cured leaf C3F from pot-cultured New K326 and Yunyan 87 growing at the altitudes ranging from 200m to 1200m above sea level in Shimen County and Cili County of Hunan Province were determined with Soxhlet extraction, continuous flow analytical method and flame photometry.The soil matrix, planting population, fertilizing rate and schedule, and culture practices were one and the same.The results showed that:1)the petroleum ether extract in flue-cured tobacco was significantly positively correlated with the altitude (P <0.05);2)the total nicotine and total nitrogen were negatively correlated with the altitude, the significance for New K326 was P <0.05 and for Yunyan 87 was P <0.01;3)the correlations of reducing sugar and its ratio to nicotine with the altitude were positive, the significances for New K326 and Yunyan 87 were P <0.01 and P <0.05, respectively;4)the contents of chlorine and potassium were scarcely affected by the altitude.It was concluded that the aroma concentration, harmony between major chemical components, hence, the usability of flue-cured tobacco would be better when the tobacco was planted at a moderately higher altitude.