Si3N4 ceramics have attracted much attention in the field of high temperature wear resistance because of high temperature resistance, corrosion resistance, wear resistance and hardness. In this paper, the plane friction and wear properties and mechanism of Si3N4 ceramics when wearing with C/SiC ceramics or GH214 superalloy at high temperature were investigated. The results show that the friction coefficient of Si3N4 ceramics against C/SiC ceramics increases first and then decreases with the increase of temperature. The average friction coefficient of Si3N4 ceramics at 1 200 ℃ is lower than 0.4, and wear marks, wear particles and SiO2 oxide film appear on wear surface. The wear forms are mainly abrasive grain wear and oxidation wear. When Si3N4 ceramics and GH214 superalloy are worn against each other, the friction coefficient increases with the increase of temperature. Meanwhile, obvious metal oxide layer is formed on the surface of ceramic samples, so the wear forms are mainly adhesive wear and oxidation wear. During the friction process of Si3N4 ceramics and two kinds of friction materials, the oxide film produced by oxidation wear has protective and lubricating effects on Si3N4 ceramics, which can effectively reduce the wear of Si3N4 ceramics matrix and improve the wear life of Si3N4 ceramics.