Marine nitrogen fixation provides essential bioavailable nitrogen sources for primary production in oligotrophic ocean. Currently, the players of N₂ fixation is known to be cyanobacteria and heterotrophic bacteria. But the figure where these players were located remained unclear. Therefore, this study used meta-analysis to figure out the mean and breadth of every diazotrophic taxa’s ecological niche and their potential occupied area. Temperature, nitrate, phosphate, radiation, dissolved iron and primary production were assumed to control diazotrophs’ distribution. In our result, the niche of Trichodesmium expanded to area colder than previous thoughts but UCYN-A was a cold type diazotrophs as commonly acknowledged. Non-cyanobacterial diazotrophs were also counted in analysis, and its estimated ecological niche were similar to cyanobacteria counterparts, implying its potential photoheterotrophic feature. Meanwhile, UCYN-B and RIchelia both show a great demand for iron. Therefore, our ecological niche study provides an important implication of nitrogen fixers distribution for future study.