The experiment was conducted to study the possibility of enhancing the arbuscular mycorrhizal fungi root infection with the combined inoculation of Methylobacterium sp. isolates obtained in the present study. The study was carried out with methylobacterial isolates such as Methylobacterium sp. LE1, Methylobacterium sp. AI1 were combined inoculated with AM fungi to find out mycorrhizal root colonization on onion plant. From the above findings, treatment such as T6 (Methylobacterium sp. AI1+AM fungi) followed by T5 (Methylobacterium sp. LE1+AM fungi) responding better for co inoculation which resulted in a significant interactive effect on spore count and mycorrhizol root colonization compared to untreated plants. In addition, the combined inoculation of (Methylobacterium sp LE1+AM fungi) resulted in superior consortium of microorganism for inoculating onion. The mixed microbial inoculants were promoting the plant growth by producing growth hormone, mineral compounds and humanizing soil conditions. However, overall obviously the combined treatment was better for onion.