Two separate experiments were carried out in a private farm in El-Matria; Dakahlia Governorate, Egypt during two successive seasons 2009/2010 and 2010/2011 to study the effect of potassium sources (potassium mono phosphate 52% K₂O potassium sulphate 50% K₂O and potassium citrate 38% k), levels (0, 60 and 120 kg K₂O/ fed for each source), phosphorus sources (calcium super phosphate 15.5 % P₂O₅, rock phosphate  30 % P₂O₅ and phosphoric acid  85 %P₂O₅)  and levels  (0, 30 and 60 kg P₂O₅/fed  for each source)  on  vegetative growth,  tuber  yield and chemical constituents of potato (Solanum  tuberosum  L.) "Spunta". Treatments were arranged in randomized complete block design in three replicates. The obtained results indicated that both potassium mono phosphate  at  120 kg K₂O/fed  and  phosphoric acid at 60 kg P₂O₅/fed  gave the  highest  values of  vegetative  growth  parameters, tuber yield and its quality in both seasons as compared with other treatments and the differences were significant.