Tow Field Experiments were carried out at EL-Itizaz village, Samalout district, EL-Minia Governorate, Egypt during 2004/2005 and 2005/2006 seasons to study the effect of foliar with potassium, magnesium and boron individaly and combined on yield and quality of sugar beet. The experiment included 15 treatments which were the combinations of two levels from each of foliar potassium 1 and 2 Liter 36% K₂O/fed, with 5.4 and 10.8 kg MgSo₄/fed, boron (10 and 20 mg boric acid/fed) and control (foliar spray with water). These treatments were arranged in randomized complete block design with 3 replications. The obtained results indicated that spraying beet plants with K, Mg or boron either solely or in combinations significantly increased root length, root diameter, root and foliage fresh weights per plant as well as roots, top and sugar yields/fed. The highest values of this traits resulted from the combinations between the three elements at higher concentrations. Also, foliar spray with Mg individual and the combinations between the three elements took the same trend for root/top ratio in both seasons. On the other hand, control treatment (without spraying) gave the maximum averages of sucrose and TSS percentages, while the highest values of purity% resulted from foliar spray with the combinations between K, Mg or B at lower concentrations in both seasons. It, could be concluded that under the conditions of this study the highest roots and sugar yields can be produced by using foliar spray with the combinations.