Two fieid experiments were carried out during the summer seasons of 2002 and 2003 on potato cv. ( Spunta ) in clayey loamy soil at El-Baramoon Res .Station, Mansoura, Dakahiia Governorate, to study the effect of foliar application with organic compounds i.e. ascorbic acid ,citric acid and oxalic acid and their combinations with the nitrogenous fertilization at rate of (150 kg/fed) compared with similar rate of nitrogen fertilization alone without foliar application on vegetative growth, yield, tubers quality and some chemical contents of foliage and tubers. Results showed that the foliar application with mixture of (ascorbic acid + citric acid) at rate of (7'50+750 ppm)‘L twice at 7 and 9 weeks after planting was very effective on vegetative growth parameters Le, plant height (cm) ,fresh weight of foliagefplant (g) and dry weight of foliage (0/0) ; as well as , average of the tuber weight (9) ,total tubers yield (ton/ feddan) , dry matter of tuber (%) and starch content of tubers (%)compared with the other treatments . On the other hand , the main stems number I plant , number of tubers/piant and tuber content of protein (%) were not affected significantly by the different treatments during the two seasons . N, P and K contents in both leaves at 90 DAP and tubers at harvest were significantly increased by applying the foliar spraying with mixture of (ascorbic acid + citric acid) at rate of (750+?50 loprri)‘L in the two summer seasons of 2002 and 2003 . The results revealed that applying the foliar spraying with mixture of (ascorbic acid + citric acid at rate of 750 + 750 ppm)'L on potato plants twice at 7 and 9 weeks after planting under conditions of nitrogen fertilization at rate of 150 kgifed. ted to increase of vegetative growth parameters and increment of total tubers yieid/fed by 12.88% (average of two study seasons), as well as tubers quaiity improvement compared with the same rate of nitrogen fertilization alone without foliar application by organic compounds (control).