To investigate the effect of nitrogen and yeast rate, as well as number of magnesium application on sugar beet yield and quality, two field experiments were carried out at the Experimental Farm of Sakha Agric. Res. Station, KaferEL-Sheik Governorate, Egypt, during the two successive seasons  of  2013/2014 and 2014/2015. Split-split plot design was used in both growing seasons. Three nitrogen rates (75, 85 and 95 kg N/fad) were arrange in main plots, two yeast rates (10, 15 g/l) were devoted in sub-plots, whereas, sub-sub plots were allocated to number of magnesium applications at rate of 6 g/l  (without addition, one, two and three times). Main results could be summarized as follows: Increasing nitrogen rates from 75 to 95 kg N/fad significantly increased the most characters under study such as, root dimensions, top/ root ratio, in the second seasons sugar beet yields (top, root and sugar), impurities values as well as sugar loss in molasses and alkaline coefficient in term (AC). On the other direction, juice quality significantly decreased such as sucrose%, extractable sugar, extractability and purity percentages as nitrogen level increased. Application of yeast at the rate of 15 g/l significantly affected yield and quality and caused a significant increase in the most characters under study as compared to the rate 10 g/l which gave lowest values for all traits under studied trails. Application of study take the same trend of nitrogen fertilizer effect. Number of magnesium application as foliar spray at the rate of 6g/l significantly affected the most studied characters. Three times, significantly increased sugar beet yield and its attributes, while it significantly decreased quality values for some traits as sucrose%, extractable sugar and extractability percentages.  It could be concluded that adding nitrogen fertilizer at the rate of 95 Kg N/fad and yeast at the concentration of 15g/l as well as application of magnesium three times at the rate of 6g/l is a recommended treatment for maximizing sugar beet yield and its quality under these conditions of this study.