Two field experiments were conduct at Sakha Agric Res.  Station ,  Kafr El-Sheikh Governorate during 2008/2009 and 2009/2010 seasons. The objectives of this study aimed to study effect of three nitrogen levels (75 , 90 and 105 kg N  /fad) and two  nitrogen sources (ammonia gas 82 % and urea 46 % N ) on yield and quality of sugar beet under environmental conditions of Nile Delta region . The main findings could be summarized as follows: Application of nitrogen fertilization at the rate of 105 kg N / fad in the form of ammonia gas by 6 days before sowing gave the highest values of chastises i.e root, sugar and top yields as well as top/root ratio, Na, K ,a-amino nitrogen content and sugar loss in molasses in both seasons .On the contrary , sucrose , purity , sugar extractable , extractability percentages and alkaline coefficient recorded  the lowest values in both seasons. Application of ammonia as a source of N significantly increased, root and sugar yields, sucrose and purity % as well as sugar extractable and extractability % and alkaline coefficient . Generally, it could be concluded that application of ammonia gas at 6 days  before sowing for   late sowing at the end of October gave the highest root yield and quality for sugar beet compared that fertilized by urea which applied late after sowing as another nitrogen source.