【Objective】The effects of the combined application of N and K fertilizer on aroma composition and sensory quality of flue-cured tobacco were studied in order to improve the tobacco quality and its industrial usability.【Methods】Field experiment was carried out using tobacco variety K326 as test material. Three nitrogen levels， viz.， low nitrogen ( 45 kg/ha )， medium nitrogen (90 kg/ha ) and high nitrogen (135 kg/ha )， and three potassium levels， viz.， low potassium (180 kg/ha)， medium potassium (270 kg/ha) and high potassium (360 kg/ha) were applied in 9 combinations and their effects were observed on aroma composition and tobacco quality. 【Result】The combined application of medium nitrogen (90 kg/ha ) with high potassium (360 kg/ha) was found good for the formation of neutral aroma composition， while the treatment of high nitrogen with low potassium (180 kg/ha) was good for the formation of acid aroma composition. The treatment of high nitrogen (135 kg/ha) with high potassium (360 kg/ha) enhanced the formation of saturated fatty acid and decreased the formation of unsaturated fatty acid. The smoking evaluation score of leaves was highest in treatments with medium nitrogen and medium potassium， while that of treatments with low nitrogen and potassium， and low nitrogen and medium potassium recorded lowest scores. 【Conclusion】Considering several factors， such as yield， score of smoking evaluation， aroma composition and chemical composition， the medium nitrogen (90 kg/ha) application with high potassium (360 kg/ha) was the best， and the treatment of middle nitrogen (45 kg/ha) with high potassium (180 kg/ha) was not suitable for tobacco production.