Tribological properties of a-C:H coatings has been investigated in various friction conditions. It is clear that temperature and mating materials give effects on tribological properties. In this study, we especially focus on the effect of mating material on its tribological properties of a-C:H coatings. Ball-on-disk friction test is conducted between a-C:H coating and 5 kinds of mating material, which is SiC, SiC(O)_800 (SiC oxidized at 800°C), SiC(O)_1050°C, SiC(O)_1300°C, and Quartz glass. It is found that a-C:H coatings shows low friction coefficient and low specific wear rate when O/Si ratio of the element content of mating material is 2, in other words, mating material is SiO2. In the wear scar of a-C:H coating after friction test with SiC, severe damage was confirmed. It is considered that a-C:H coating and SiO2 show low adhesion even at high temperature, which leads low friction and wear. Compared SiC(O) with Quartz, the friction coefficients with a-C:H coatings are respectively 0.013 and 0.038. Even though SiC(O) and Quartz are both SiO2, the tribological properties are different. On the wear track of SiC(O), transferred things from a-C:H coating are confirmed.