Field trials were conducted on a new flue-cured tobacco line JSZX–09–011 to study the influence of potash fertilizer management (K2O application being 135, 180 and 225 kg/hm2 with the ratio of basal to top-dressing K fertilizer being 3∶7, 5∶5 and 7∶3 respectively) on photosynthesis, yield and quality of flue-cured tobacco grown in Panxi tobacco-growing areas in Sichuan. The results showed that leaf area index (LAI), net photosynthesis rate and yield of tobacco plants all showed great advantages in treatments with potash application at 180 kg/hm2compared to other treatments. Tobacco plants with postponing K fertilizer improved the canopy structure and consequently increased the photosynthesis efficiency. With the increasing of top-dressing K fertilizer, the SPAD value of canopy leaves raised significantly which is in favor of improving the photosynthesis efficiency of tobacco plantswhile ; nicotine content of tobacco leaves showed a decreasing tendency, and the ratio of sugar to nicotine and the proportion of potash came into a balance, which greatly improved the quality of tobacco leaves. In general, under medium fertility condition of Panxi tobacco-growing areas, potash applied at 180 kg/hm2 integrated with ratio of basal to top-dressing potash being 3∶7 was beneficial to coordinate the yield and quality of flue-cured tobacco, which will enhance the industrial applicability of tobacco leaf.