The properties of C/C composites with different graphitization temperatures and mixed matrix carbon were investigated by nanoindentation. The results show that the nanoindentation modulus of C/C composites with graphitization temperature of 2 500 ℃ was 10% lower than that of C/C composites with graphitization temperature of 2 300 ℃. The highest modulus of resin carbon is measured by nanoindentation in C/C composites with mixed matrix of pyrolytic carbon， resin carbon and asphalt carbon， followed by pyrolytic carbon and the lowest by asphalt carbon. The surface fracture toughness of the C/C composite micro-component was finally obtained as 0.492 MPa•m^1/2 by nonlinear fitting of the nanoindentation load displacement curve after finite element calculations.