Abstract: A field experiment was conducted to study the effect of different kinds of potassium (K) fertilizers on agronomic attributes, chemical components and economic values of flue-cured tobacco in two typical ecological zones in Shaanxi province. The results showed that K fertilizer had significant effect on leaf area. The effect of potassium nitrate was better than that of potassium humate in Longxian;the effect of potassium humate was the best, followed by mixed k fertilizer. K application increased contents of total sugar, reducing sugar, nitrogen, nicotine and potassium, and decreased the content of chlorine, and these effects varied with ecological zones. Leaf chemical composition was more harmonious with potassium humate or mixed K fertilizer treatment. In addition, main economic values increased significantly with K fertilizer treatment, and better effect was observed with treatment of mixed K fertilizer in Longxian, but potassium humate and mixed K fertilizer in Luonan. Overall, mixed K fertilizer was preferred in Longxian, and potassium humate or mixed K fertilizer in Luonan. K application was useful to optimize leaf chemical components, improved leaf quality and increase yield, but these effects varied with ecological zones.