The effects of decreasing chemical potassium after application of biotic potassium on content of aroma components and smoking quality in flue-cured tobacco leaves were studied by field experiments. The results showed that application of decreasing chemical potassium after biotic potassium application did not reduce contents of total aroma components and major aroma components and the treatment of decreasing chemical K2O by 14% was better. The application of decreasing chemical potassium after biotic potassium application also could obtain good smoking quality and high economic benefit, but this result was unstable and needs further study for developing and applying biotic-potassium fertilizer.