This paper deals with the effects of the rates of potassium fertiliser application rates and the potassium status of three typical tobacco planting soils on the K contents of flue-cured tobacco organs,K distribution,and secondary and trace element contents of cured leaves.The results indicated that K content in cured leaves increased with the potassium rate,which could be fitted by equations.When tobacco was supplied with sufficient potassium fertilizer,the order of K content on plant organs was bud>leaf>stem>root,and on different leaf positions was lower>middle> upper; but in K dificient condition the leaf K content in upper position was higher than that in middle and lower.The percentages of K distribution in tobacco organs were in the sequence Leaf>stem>root>bud.When K content in middle leaf was upper to 2.4% or more,the distribution tended to be balanced and the percentage tended to a constant,being 60%,20%,15% and 5% in leaf,stem,root,and bud,respectively.So,2.4% of K content in middle leaf could be taken as the Critical Value for Balanced Distribution of Potassium under the experimental conditions.The Critical Value gives a new idea to improveing the potassium nutrition of tobacco.