A SiC/MoSi2-ZrB2 ceramic coating was prepared by a magnetron sputtering method on carbon/carbon composites to protect it against oxidation. The microstructure of the coating was investigated, and its oxidation behavior at 1273K and 1773 K in air was also studied. The as-received coating exhibited outstanding uniformity in thickness and presented columnar structure. The coated C/C composites performed a superior oxidation resistance, and the weight loss of the samples after oxidation at 1273K and 1773 K for 60min in oxygen containing environment was 5.6×10-2 g/cm2 and 6.3×10-2 g/cm2 , respectively.