Objective To investigate the effect of different oxide additives on the phase composition, microstructure and oxidation resistance of the SiC-ZrC coated C/ C composites. Methods SiC-ZrC coated C/ C composites were prepared by a pack cementation technique with different oxides (Al2O3, B2O3 or MgO) as additives. The anti-oxidation property of the SiC-ZrC coated C/ C composites was also studied in the temperature range between 1000 ℃ and 1550 ℃ in static air. Results The results showed that Al2O3 and MgO additives exhibited better performance in enhancing the diffusion of the embedding powder materials than B2O3 additive. The SiC-ZrC coating prepared with Al2O3 as an additive was more compact than that prepared with MgO as an additive. The weight loss of the SiC-ZrC coated C/ C composites prepared with Al2O3 as an additive decreased gradually with the increasing oxidation temperature in the temperature range of 1000 ~ 1550 ℃ , and the weight loss was about 1% after oxidation at 1550 ℃ for 1 h in air. However, the weight loss of the SiC-ZrC coated C / C composites prepared with B2 O3 or MgO as an additive increased with the increase of the oxidation temperature. After oxidation for 1 h, the weight loss of the composites prepared with B2 O3 and MgO as additives reached 15% and 36% , respectively. Conclusion The SiC-ZrC coated C / C composites prepared with Al2 O3 as an additive had good oxidation resistance at high temperature.