Abstarct: The experiment was determination of Mycorrhizal fungi, Rhizobium and Thiobacillus Bacteria Inoculation on growth and yield of cow pea during growing season of 2014 at the Azad University Agricultural Research Station located in shahr-e-rey. The factors were consisted of mycorrhiza inoculation, in three levels of inoculation with G.mosseae (m1), G.intraradices (m2) and non-inoculated (m0), rhizobium in two levels of inoculation (r1) and control (r0) and thiobacillus in two levels of inoculation (b1) and control (b0). Results show that inoculation of mycorrhiza, rhizobium and thiobacillus increased stem height, pods per plant, seeds per pod, sheath dry weight, leaf area index, weight of 100 grains, grain yield and biological yield, harvest index, root colonization percentage, chlorophyll index, leaf cholorophyll and carotenoides seed protein percentage and nitrogen percentage significantly compared to controls. Seed Phosphorus percentage and relative water content were only affected by the using of mycorrhiza. Interaction between of mycorrhizal and rhizobium bacteria on increasing seeds per pod, sheath dry weight, biological yield, grain yield chlorophyll a and carotenoids were significant. The interaction of mycorrhizal and thiobacillus on increasing Sheath dry weight was significant. Also, interaction of mycorrhizal, rhizobium and thiobacillus on increasing sheath dry weight and grain yield were significant.