Abstract: Using Marine microorganisms isolated and cultured from deep-sea sediment samples, the accumulation and mineralization of rare earth element Ce by several marine bacteria (Jeotgalibacillus sp., Paenisporosarcina sp., Sulfitobacter sp.) were simulated. The interaction between marine bacteria and Ce was analyzed by inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscope (SEM), transmission electron microscopy (TEM), and other analytical methods. It was found that the three bacteria species could adsorb and enrich Ce, and the efficiencies of the adsorption and enrichment by the marine bacteria were mainly related to the bacteria density and the Ce concentration. In addition, the adsorption capacity of different marine bacterium to Ce was different. In the process of adsorption, enrichment, and mineralization of rare earth Ce by marine bacteria, rare earth Ce was first adsorbed at the cell surface to form nucleation cores, and then mineralized to form amorphous-structured mineral particles containing Ce on the cell surface. At last, the process and mechanism of rare earth mineralization enriched by marine microorganisms were further discussed.