Abstract:The simplex-lattice design was applied to study the effect of ration of different kinds of controlled release potassium (CRK) fertilizer and conventional potassium fertilizer,blended controlled release potassium fertilizer on production and potassium content in leaves of flue-cured tobacco under field condition.The results showed that the use of blended CRK fertilizer,combined application of controlled release potassium fertilizer with water soluble conventional potassium fertilizer could significantly increase the potassium content in leaves. The effect of T7 treatment (52.150 kg/hm2+ 96.850 kg/hm2+74.500 kg/hm2) was maximum.K content of both T7 and T1 treatment (67.050 kg/hm2+89.400 kg/hm2+67.050 kg/hm2) increased by 35.17% and 31.65％,respectively.T7 treatment and T1 treatment could also increase the production of lower leaves,middle leaves and upper leaves of the tobacco with obvious increase of lower leaves and upper leaves.The yield of T7 and T1 treatment increased 8.9% and 7.0%,respectively.