A field experiment was conducted at Bilqas distrect, Dakahliya Governorate, Egypt to evaluate the effects of potassium rates, bio foliar fertilization on yield and quality of sugar beet (beta vulgaris L.) during 2014/2015 and 2015/2016 winter seasons. Split plot design with three replicates was performed. The main plots were assigned by three levels of potassium fertilization of (0, 24 and 48 kg K₂O fed^-1) added as potassium sulfate (48% K₂O). The sub plots were occupied by (four treatments) 1-Untreated control. 2- bio-fertilizer (potassium solvent bacteria) Bacillus circulans 3-Foliar fertilization of potassium humate at the rate 1 L fed^-1 per 400 liter water. 4- Foliar fertilization of boron at the rate 1 L fed^-1 per 400 liter water. Data revealed that the highest mean values of fresh weights of shoots and roots, sugar yield (kg fed^-1), N%, K%, sucrose% and quality% in roots of sugar beet were obtained from 48 kg K₂O fed^-1 fertilization with boron treatment compared with all the other treatments. Meanwhile, the lowest values were obtained from the control without K fertilization and without boron fertilization during both seasons. Sodium (Na %) decreased with increasing potassium fertilization in both seasons. It is worthy to that both bio K fertilization and K humate addition also had positive effects during both seasons.