Two field experiments were conducted at the Mallawi Agricultural Research station . A.R. C El-Minta Goveranorte , during the two succes-sive season of 1997/98 and 1998/99 to study the effect of Biofertilizer Bl-Biogen and B2 -Cerealin and the rate of application recommended for nitrogen fertilizer )0 (control) - 20% - 40% and 60% of recommended N rate on yield and yield components of two barley cultivars , Giza 126 and Giza 123. A split- split plot design with four replications was used . Barley varieties were the main plots , Biofertilizer in the sub -plots while the nitrogen fertilizer treatments were alloted to the sub -sub plots . The results indicated that : 1. Giza 126 gave the highest number of plants / m2 and was later in heading than Gin 123 variety . 2. The application of the blofedilizer Mogen • significantly Increased grain ytleld of barley by 25.53 % and 12.34 % compared to applica‌tion of the biofertilizer cerealin. 3. The application of biofertilizer ( biogen) significantly increased straw yield of barley by 17.51 % and 31.85 % compared to the application of mean . 4. Biogen significantly improved number of plants / m2 , plant height and number of kernels / spike compared to cerealin 5. There were no differences among nitrogen fertilizer treatments on grain yield in both seasons . 6. The highest grain yield was produced from biofertilizer Mogen using 20% of the recommended nitrogen fertilizer rate in the first season . while the highest number of plants / m2 number of kernels / spike and plant height were obtained from Biogen on Giza 126 variety in the second season -But the highest number of kernels/ spike result‌ed from using 60% of the recommended N rate and Biogen in the second season.