Sugar beet is complementary sugar crop to bridge the gap of sugar production. Two field experiments were carried out during the two successive winter seasons of 2010/2011 and 2011/2012 to study the effect of compost and foliar spray with magnesium on improving some soil properties, photosynthetic pigments, productivity and quality of sugar beet crop (Kawemira cv.) at Deyma village, Gharbiya governorate, Egypt. The experiment included twelve treatments which were four rates of compost (0, 2, 4 and 6 ton/fed.) and three levels of foliar application with magnesium (0, 2.5 and 5 Kg MgO /fed.). Split plot design with three replicates was used. The obtained results revealed that application of compost at any rate improved the soil properties (reduced the bulk density, soil pH, EC and Soluble ions of Na+, HCO3- and Cl-, However, improved total porosity, field capacity, available water, soil organic matter, and soluble ions of Ca+2, Mg+2, K+ and SO4-2. The highest amount of compost application surpassed the other rates in enhancing the determined soil properties. The tested compost rates showed significant differences for most of studied characters in both seasons. Raising compost rates up to 6 ton/fed gradually increased the photosynthetic pigments, yield and quality of sugar beet (top yield, root diameter, root length, sucrose %, juice purity %, sugar yield and extractable sugar yield) and nutrients uptake in the tops and roots. Foliar feeding with magnesium had a marked effect on photosynthetic pigments, maximize yield and quality of sugar beet. The highest values of these traits were obtained by application of 5 kg MgO /fed in the two seasons. On the other hand, unsprayed plants produced the lowest ones. The interaction between compost rates and magnesium levels were significant for most characters. Also it was noticed that application of compost at a rate of 6 ton/fed combined with foliar application of 5 kg MgO/fed gave the best results for improving soil physical and chemical properties and achieving the best crop by improving its nutrients content under the condition of the current study.