The present work was conducted at Tamiya, Fayoum Governorate in 2001/2002 and 2002/2003 seasons to study the effect of water quality and nitrogen fertilization on yield and quality of some sugar beet varieties. Each trial included tewenty four treatments represent the combination between two qualities of irrigation water (fresh and brackish water), three nitrogen levels (60,75 and 90 kg N/fed) and four sugar beet varieties (two polygerm , Beta-Poly 4, Ras-Poly and two monogerm, Tora, Helx). A split plot design with four replications was used. The obtained results showed that root length , root yield, and sucrose% were affcted significantly by water quality in both seasons . Supplying sugar beet plants with brackish water recorded the highest values of sugar yield compared with those watered with fresh water. Sugar beet varieties differed sgnificantly in root length, root girth, sucrose %, root and sugar yields in both growing seasons. Increasing N-level from 60 up to 90 kg N/fed, significantly increased root length, root girth and sucrcse%, purity % as well root yield in both seasons. Sugar yield was significantly affected by adding N fetilizer in the 1st season only.