In order to investigate the effect of nitrogen and potassium fertilizers on yield and mineral accumulation of cv.coker347 and cv.k326 of flue-cured tobacco, 2 year experiment was carried out in tobacco research institute of Rasht located in Guilan province on factorial based with 3 replications. The applied fertilizer levels included 35(N1), 45(N2), 55(N3) and 65 (N4) Kg/ha of pure nitrogen from urea source, and potassium in two levels of 150 (K1) and 200 (K2) Kg/ha potassium from potassium Sulfate. The measured parameters in this experiment included dried leaf weight, stem nitrogen, stem potassium, stem phosphorus, leaf nitrogen, leaf phosphorus, leaf potassium, plant nitrogen, plant phosphorus, plant potassium, nitrogen harvest Index, potassium harvest Index, phosphorus harvest Index. The effect of variety on dried leaf yield, stem nitrogen and plant potassium was significant on 1% level, and the variety had also significant effect on leaf potassium, plant nitrogen and nitrogen harvest Index on 5% level. The nitrogen had significant effect on parameters such as stem nitrogen, plant nitrogen on 1%level and similarly had significant effect on stem phosphorus, stem potassium and potassium harvest Index on 5% level. The potassium had significant effect on dried leaf, stem potassium on 1% level and also on plant potassium, potassium harvest Index on 5% level. The interaction between cultivar and nitrogen was significant on parameters like dried leaf yield, stem potassium, leaf nitrogen, plan nitrogen, plan potassium, nitrogen harvest Index and potassium harvest Index on 1% level and it was significant on stem nitrogen and leaf phosphorus on 5%level. The interaction between cultivar and potassium was significant on dried leaf, stem nitrogen, stem phosphorus, leaf nitrogen, leaf potassium, potassium harvest Index and nitrogen harvest Index on 1% level. This interaction on stem potassium www.ccsenet.org/jas Journal of Agricultural Science Vol. 4, No. 2; 2012 ISSN 1916-9752 E-ISSN 1916 168 was also significant on 5 % level. The interaction between nitrogen and potassium was significant on stem phosphorus, leaf potassium and potassium harvest Index on 1% level. This interaction on dried leaf yield, stem phosphorus, leaf nitrogen, and plant nitrogen and plant phosphorus was also significant on 5%level. The interaction among cultivar, nitrogen and potassium on parameters like dried leaf yield and stem phosphorus was significant on 1% level and this interaction on 5% level was also significant on plant potassium, leaf potassium and potassium harvest Index on 5% level