PAN-based carbon fiber (CF) was modified in different ways by authors. The current multiple modification treatment composed of surface oxidation, maleic anhydride (MA) graft and metalion-adsorption was regarded to be a favorable surface treatment for CF carrier. The CF surface morphology and natures were characterized by specific facilities, such as laser confocal microscopy (LCM), X-ray photoelectron spectroscopy (XPS) and the degree of moisture. On the other hand, the biocompatibility nature was indicated by immobilization results of microorganisms on CF. The results show that the surface hydrophilicity and roughness of CF, and the metalion adsorbed on the CF surface would contribute greatly to biofilm formation and improve the immobilization ability of microorganisms on CF surface. Furthermore, the configurations and the adhesion forms of cells were obviously affected by the properties of CF surface.