Field experiment was conducted to study the effects of the combining application of N, P and K fertilizers on the contents of petroleum ether extracts and aroma constituents in flue-cured tobacco leaves of a tobacco (Nicotiana tabacum L.) cultivar Zhongyan100. Results showed that the contents of petroleum ether extracts, total aroma constituents and different kinds of aroma constituents in tobacco leaves were the lowest in the treatment without fertilizer (CK). Combining application of any two of N, P, K could increase the contents of petroleum ether extracts and aroma constituents. With the increment of N, P, K fertilizers, petroleum ether extracts in flue-cured tobacco leaves increased continuously, while the content of aroma constituents increased at first then decreased, showed a shape of parabola. Therefore, reasonable combining application of N, P, K fertilizers is an important and effective measure in improving petroleum ether extracts and total aroma constituents in flue-cured tobacco. The recommended fertilization derived from field experiment is N:P2O5:K2O = 1:2:3 with the amounts of N, P and K fertilizers of 75 kg/hm2, 150 kg/hm2 and 225 kg/hm2 respectively.