We demonstrate the regulation of metal-support interactions (MSI) by impregnating Co(NO3)(2) as a precursor of cobalt over the silica coated with different amounts of amorphous carbon via carbonizing the glucose as a precursor in the inert atmosphere of an Ar. The materials were characterized by XRD, H-2-TPR, H-2-TPD, XPS, O-2 titration, and N-2 adsorption-desorption at low temperatures. In comparison with the parent 10 wt% Co/SiO2, the Co-supported carbon-coated SiO2 (10 wt% Co/xC-SiO2) showed obviously higher dispersion of the metallic cobalt (Co-0) and smaller Co-0 particle size. Moreover, the Co-0 dispersion was increased and the Co-0 particle size was decreased with increasing the carbon content over the catalysts. The weakened MSI between Co-0 and the xC-SiO2, the extent of which is dependent on the carbon content, was clearly revealed from the characterization results. This was further supported by the reaction results of Fischer-Tropsch synthesis (FT), and the highest CO conversion was obtained over 10 wt% Co/1C-SiO2. The simple procedure and the cheap glucose make it important for developing a more efficient FT catalyst.