Two field experiments were carried out at a private farm at Dahtara village. Zefta District, Gharbeya Governorate, Egypt, during 2014 and 2015 Summer seasons. This work aim was to study the effect of nitrogen sources and bio-fertilization on growth, yield and its components and yield analysis of some maize hybridsThe maize hybrids used were: Single cross 166 ( SC166) , Single Crass 176 (SC 176 ) and Three Way Cross 352 ( TWC 352). Three nitrogen sources were tested i.e. Ammonium sulphate, Ammonium nitrate and urea . Three bio-fertilizer rates were used : 0 gm. cerealin/Fad, 250 gm. cerealin/ fad and 500 gm. cerealin/fad. The experimental design was Split-Split plot with three replication . Maize hybrids were allotted in the main plots, wile the three nitrogen sources and the three bio-fertilization treatments were arranged at random in the sub and sub-sub plots, respectively .The subplot consisted of 6 ridges each with 4m long and 70 cm width This work was performed to investigate the effect of source of nitrogen and bio- fertilizer on growth, yield and yield components of three maze hybrids (S.C. 166, S.C.176, and T.W.C35 under Egyptian conditions.