Many toughening methods have been developed to improve fracture toughness of alumina ceramics, and continuous fiber reinforcement has been demonstrated to be the most effective method.In comparison with 1D (1 dimensional) and 2D fiber reinforcement, 3D reinforcement possesses advantages such as higher interlaminar shear strength, easiness of complex shapes, and feasibility of property design by orientation and volume fraction of fibers.The densification route of repeating infiltration and heat treatment with AlCl3 or Al(NO3)3 solution as raw materials has been adopted to fabricate 3D fiber reinforced Al2O3 composites [1,2].This route is relatively inefficiency due to the low content of solid in solution.To raise the preparation efficiency, it is necessary to use sol with high solid content as raw materials [3,4].In this paper, alumina composites reinforced by carbon fiber cloth preform with a laminated and stitched structure were fabricated through the route of vacuum infiltration-drying-heat treatment by using Al2O3 sol with high solid content as raw materials.The C/Al2O3 composites with a naked interface and a total porosity of 14.6% show 202.1MPa in flexural strength and 9.32MPa.m1/2 in fracture toughness.Due to further sintering of Al2O3 matrix and compressive stress derived from thermal mismatch between fiber and matrix, the flexural strength decreases by 15.5% after anneal at 1700 ℃ for 1h under inert atmosphere.In consideration of porosity and naked interface, the mechanical properties and high-temperature stability are favorable and have a large margin for improvement.The oxidation resistance of C/Al2O3 composites is deficient as a result of high porosity and can be effectively improved by incorporating mullite in matrix.