Abstract: In order to research the applicability of Ti(C,N)-based cermets at high temperatures.Oxidation behavior and mechanism at 900-1 150℃ of the lermet material were investigated by means of XRD,SEM,EDS.The results show that from 900 to 1 150℃,the oxidation degree obviously increased with the elevation of temperature,and the curves of gained mass were liner to parabola.After oxidation at 900℃ for 100 h in the air,thickness of the compact oxide layer generated on the surface of the material was less than 10 μm with composition of NiO＋TiO2,which could protect the matrix.While on the condition of 1 150℃,loose layer with the main composition TiO2 derived from the inner compact one with thickness more than 80 μm,which lost the protection to matrix gradually.