ZrB_2-SiC-ZrC (ZSZ), which is known as one of ultra high temperature ceramics (UHTCs) composite material, with four different compositions containing 16 vol.%SiC and ZrB_2-16 vol.%SiC were sintered by spark plasma sintering. These sintered compacts are oxidized at 1700 ℃ by IR image furnace in airflow. The result showed that all samples were covered with SiO_2 and ZrO_2. Moreover, oxide scale of ZSZs containing higher ZrC than ZrB_2 has been damaged. Observation of the cross-section of all samples revealed that oxide area was consist of five different layers: SiO_2 layer, SiO_2 with ZrO_2 layer, SiC-depleted layer and unoxidized area. Furthermore, the thickness of oxide layer of ZSZs containing more ZrB_2 than ZrC was thinner. Thus, it was expected that these samples have good resistance to oxidation.