Two field experiments were carried out on a clay loamy soil at the experimental field of the Agricultural Research Station Sabaheia, Alexandria during 2001 and 2002 seasons, to study the effect of three levels of a mineral nitrogen fertilizer (40, 60 and 80 kg N/fed in urea form) and three levels of biofertilizer (0, 800 and 1600 g cerealin/fed) on sweet sorghum var. Collier. The experiments design was a split plot with four replications. The results showed that leaf area (cm2), stalk yield (ton/fed), juice yield (ton/fed), total soluble solids % and sucrose % were significantly responded to the mineral nitrogen fertilizer in both seasons and plant length, stalk diameter, purity % and extraction percentage in the 1' season. Cerealin application significantly increased stalk diameter, leaf area (cm2), stalk yield (ton/fed), juice yield (ton/fed), sucrose %, purity % in both seasons while total soluble solids % was significantly affected by cerealin in the lst season and plant length in the 200 season. Interaction effect between nitrogen and cerealin fertilizers significantly increased sucrose % and purity % in both seasons and juice yield and stalk yield in the 1' season. Otherwise, stalk length, diameter, leaf area and extraction % were insignificantly affected by interaction between nitrogen and cerealin fertilizers. This study recommends the application of nitrogen fertilizer at 80 kg N/fed and/or 1600 g cerealin/fed to yield the highest value of stalk yield of sweet sorghum.