The present study was conducted in the Experimental Farm, El-Khattara region, Faculty of Agriculture, Zagazig University, Sharkia Governorate, Egypt during 2009/2010 and 2010/2011 seasons. The study aimed to investigate the effect of nitrogen fertilizer levels (50, 75, 100 and 125 kg N/fad.) and biofertilization treatments (control, cerialine, potassiomag as well as cerialine + potassiomag) on yield and its attributes as well as juice quality of sugar beet under drip irrigation in sandy soils. Nitrogen fertilizer level had significant effect on all traits in the two seasons and their combined analysis. Increasing N fertilizer levels from 50 to 125 kg N/fad., caused significant increase in root dimensions (length and diameter), fresh top weight/plant, fresh root weight/plant, Na%, K%, sugar loss in molasses percentage (SLM%) and root yield/fad. Top and recoverable sugar yields were responded only to 100 kg N/fad. The highest averages of sugar%, purity% and extractable sugar % were produced from using low nitrogen levels (either 50 or 75 kg N/fad.). Biofertilization treatments had significant effect on root length, fresh top weight/plant, fresh root weight/plant, Na%, K% as well as top and root yields/fad. However, root diameter, sucrose%, alpha amino N%, purity%, SLM% and alkaline coefficient (AC) did not significantly influenced by applying biofertilizers. The highest recoverable sugar yield/fad., could be obtained by using either cerialine alone or in combination with potassiomag. The interaction between studied factors revealed significant effect on fresh root weight/ plant, sucrose%, Na% and extractable sugar%.