The cashew nut shell oil modified phenolic resin matrix friction materials with addition of different ratios of carbon fiber and glass fiber were prepared by using a hot pressing technology.The tribological properties of the friction materials sliding against highspeed steel were studied on the ringblock tribotester under different braking conditions.The results show that when the total amount of carbon fiber and glass fiber is constant,the friction coefficient of friction material is increased with the increasing of glass fiber content,and the corresponding wear rate is decreased first and then increased.During the friction process,the wear surface of the friction materials is easily to form a layer of dense friction film,which reduces the friction coefficient and wear rate of the friction materials.And at highspeed conditions,the friction film is more likely to be formed.When the mass fraction of glass fiber and carbon fiber is 8% and 9%,the friction material shows the best tribological properties.The wear mechanism of the friction material is mainly adhesive wear.