Two field experiments were conducted in sandy soil at El-Bustan region, El Behera Governorate during two winter successive seasons of 2004/2005 and 2005/2006 to evaluate the effect of five nitrogen fertilizer levels (71.5, 143, 214, 286, and 357 kg/ha) represented (25, 50, 75, 100 and 125% of the recommended dose) and some isolates of nitrogen fixing bacteria (Azospirillum sp,, Azotobacter sp, Bacillus sp.and Klebsiellasp.) on growth and yield of six bread wheat lines. Results showed that the interaction between genotypes and nitrogen levels was significantly positive for wheat yield and its components, while the harvest index was not significant. However, the highest grain yield was obtained from the biofertilized lines numbers 15, 11 and 21 at 214 kg N/ha, lines number 8 and 21 at 286 Kg N/ha and lines 8 and 15 receiving 143 Kg N/ha. Moreover, they surpassed the grain yield of the control treatment (286 kg N/ha) by 0.80, 0.87, 0.55, 0.72, 0.59, 0.52 and 0.30 ton/ha (14, 16, 10, 13, 11, 10 and 5%) respectively. In addition, these seven combinations exceeded the commercial cultivar Sids 1 under control treatment by 1.46, 1.23, 1.04, 1.16, 1.08, 0.96 and 0.95 ton/ha (29, 24, 21, 23, 21 19 and 19%), respectively. Results also, indicated that lines: 8 and 15 expressed high stability level in grain yield due to both tested seasons. They also, outyielded the commercial check Sids 1, under biofertilization with no more than 143 kg N/ha, saving 50% of the mineral nitrogen recommended dose. Such lines should save money and environmental health. Therefore, both lines are highly recommended for yield tests in the advanced yield trails, which are conducted all over the country.