This study was carried out during two successive seasons 2014 and 2015 for evaluating the effect of inoculation with Bradyrhizobium sp, Bacillus megaterium, Bacillus circulans, Glomus macrocarpum instead a part of chemical fertilization in the presence of biocontrol agent i.e., Pseudomonas fluorescens on some microbial enzymes activity, growth characteristics, some biological constituent as well as yield and its components for optimal nutrition and some attributes of cowpeas. Obtained data showed significant increases of dehydrogenase (DH), nitrogenase and phosphatase activity in both seasons using of the combination of biofertilization and chemical nitrogen fertilization. Moreover, the values of NH₄-N, NO₃-N, available-P and soluble-K were the highest records with dual application of biofertilizers and half dose of chemical fertilization. Concerning, vegetative growth parameters and total yield, NPK-microbial inoculants combined with NPK-mineral fertilizers had the highest values. The results of this study suggest that, it may be replaced the mineral fertilizers by biofertilizers, even partially, to produce a better food and such integrated nutrient management program should be followed to produce the highest yield of cowpea.