The interaction between single and/or composite inoculant of nitrogen-fixing bacteria, phosphate-dissolving bacteria & VA mycorrhiza in association with Zea mays was investigated in a pot experiment in clayey soil under green house conditions.  The inoculation significantly increased plant dry weight particularly by composite inoculant.  The maximum increase in plant growth was recorded in triple inoculant treatments in the presence of the half-dose of N fertilizer.  Significant increase in nitrogen, phosphorus and potassium content was observed in inoculated plants, particularly with inoculants of the three microbial form, phosphate-dissolving bacteria and phosphate-dissolving bacteria + VA mycorrhiza. Full dose of N fertilization inhibited nitrogenase activity. On the other hand, the highest acetylene reduction activity was observed among maize plants roots associated with Azospirillum either in single or composite biopreparations and in the presence of ¼ N dose after 30 and 60 days.  Maize plants inoculation increased numbers of total viable bacteria, phosphate-dissolving bacteria, Azospirillum sp as well as the mycorrhizal colonization in the rhizosphere soil.  The results obtained from this work demonstrate the potential benefit of inoculating Zea mays with a composite inoculum of nitrogen-fixing bacteria, phosphate-dissolving bacteria and VA mycorrhiza.