Friction and wear tests of TiB2 sliding against SiC were conducted without lubricant from room temperature to 1200 degrees C in air and in vacuum. The friction coefficient of the couple of TiB2/SiC is affected obviously by the oxidation of TiB2. It increases with the increase of temperature and reaches a maximum at some temperature in air, then decreases remarkably. The friction coefficient of TiB2/SiC in vacuum exhibites almost a constant and keeps smaller value than that in air. Transition of TiB2 onto the sliding surface of SiC was obs...