Applicability of cyanobacteriastrains (Nostoc lichenoides, Nostoc indistinguendun, Nostoc favosum)and their mixture for effect on microbial communities  of soil under four levels of inorganic nitrogen (0, 20, 40 and60% N) was used with  recommended doses of nitrogen (70 kg N fed^–1).This experimentwas carried out in two types of soil texture (sandy and clay loam) to enumerate the number of viable bacteria, azotobacter, actinomycetes, and fungi. Results indicated that the cyanobacterial strains varied significantly and pronounced an increase in all microbes. So, the sandy soil count was lower than clay loam soil. The treatment with Nostoc favosum recorded the highest total countsof bacteria (270.9 ×10⁶ CFU/g dry soil) compared to those found by the other strains of tested cyanobacteria.  The addition of cyanobacteria to the sandy soil increased the number of Azotobacter, and the best number of azotobacter in the mixture was (52.3×10³ CFU/g dry soil) compared to uninoculated (20.5×10³ CFU/g dry soil).  However, inoculating two soil types with the mixture of cyanobacterial strains  gave the highest Actinomycetes counts compared with individual strain. Also, the treatment of types soil with the mixture of cyanobacterial strains gave the highest counts of fungi compared with any other  inoculated.  The inoculation with other cyanobacteria strains and their mixture increased the soil microbial population including, total counts of bacteria, Azotobacter, Actinomycetes, and fungi.