Two field trials were carried out at Tama, Fayium Governorate In 2002/2003 and 2003/2001 groveng seasons to evaluate two mukigerm sugar beet varieties viz Toro and Gloria grown under three N levels (75 100 and 125 kg N/fed) and three levels of magnesium sulfate (zero, 4 and 8 kg Mg0). The two operiments were as out In a sat plot design with four replications. Sugar beet varieties were allocated in the main plots whereas the sub plots were assigned for the combinations between fertilizers levels. The results showed that variety Goria surpassed variety Toro ki root length, root fresh weight, top and root yields In the l^it season only. Nitrogen fertilization at 100 kg N/fed produced significantly higher values of root length, root fresh weight and total soluble solids percentage in the 1" season and 125 kg N/fed increase] significantly sugar yield in the same season; whge 125 kg N/fed increased significantly root diameter, root fresh weight, T55 % and top yield (tons/fed) in the 2"^r season and root yield (tons/fed) in both Magnesium sulfate fertilizer attained a significant difference in root length, T55 %, root yield In the season and root fresh weight, sucrose %, purity % and sugar yield in both seasons. Increasing the magnesium sulfate level up to 8 kg MgO increased significantly root fresh weight, sucrose and purity percentages as well as sugar yield in both seasons. treanwhfie, root length, TSS % and root yield were affects by M9.50., level in the 1² season. The highest value of root yield (38.1 tons/fed) resulted from the interaction between Gloria variety, fertilized with 125 kg N/fed and 8 kg Mg0 in the 2"^/ season, while the ma:dmurn sugar yield (6.78 tons/fed) resulted from Tom variety, fertilized with 125 kg N and 4 kg Mg 0 in the 2'⁴ season.