The modification of light calcium carbonate powder was studied by wet surface modification in n-Butanol and water solution. The modification process was analyzed by modifying temperature, rotation speed, aluminate coupling agent dosage and n-Butanol percentage. The characters of modified calcium carbonate were investigated by the contact angles with water/glycerol/liquid paraffin/DOP and infrared spectroscopy (IR). The contact angles/water of modified CaCO3 powder obtained in optimum conditions was 134.5°. The results indicated that the surface property of CaCO3 powder changed from the hydrophilicity to the lipophilicity.