Oil palm plantation sector is the most important contribution to economic growth in most Asian countries and most plantations rely on chemical fertilizer for growth which caused harmful to environment. As we can see, nitrogen in the atmosphere can be fixed by the microorganism through the process of nitrogen fixation where it also can act as a bio-fertilizer. Therefore, three objectives are covered in this study, which 1) to review studies on microbial activities and their interaction with plant in soil, 2) to evaluate the effectiveness of organic matter that enhance microbe activity and also N-fixation and 3) to identify the species of bacteria and fungi used for oil palm inoculation in previous studies. A review of microbial activity has been presented in order to highlight the potential interaction where endophytic BNF bacteria have successfully increase the development of oil palm seedlings. Combination of EFB and cow dung in vermicompost technique showed the higher number of E. eugeniae (32 earthworms) thus increases available plant nitrogen. Microbial inoculation such as Glomus aggregatum, Bacillus salmalaya strain 139SI and Herbaspirillum seropedicae gives positive impact towards growth performance. The findings provided successful significant proof that microbe inoculation has a favorable influence on oil palm FFB production.