High-porosity carbon fiber reinforced carbon matrix （C/C） composites， using three dimensional needle-punched carbon fiber preforms， were prepared via the impregnation and high-temperature pyrolysis of resin containing graphite filler. The C/C composites were transformed into C/SiC composites by the reactive melt infiltration method. The phase composition， microstructure and mechanical properties of C/SiC composites were investigated. The results show that the small pores among fiber bundles are efficiently filled by resin， while the large pores in the short-cut web region are filled by flake graphite particles. The yield of carbon is evidently increased after one cycle of impregnation and high-temperature pyrolysis of resin. As-prepared C/SiC composites are composed of C， SiC and a little residual Si. The internal carbon fibers are well reserved， since the Si is not impregnated into the carbon fiber bundles. The bonding strength of fiber/matrix interface and friction force during fiber pullout can be increased due to the introducing of graphite filler， so that the C/SiC composites are strengthened. The toughness of composites is also improved， since the cracks can deflect along the flake graphite. The average flexural strength of C/SiC composites reaches to 118 MPa with a maximum strain of 1.0%， and the composites exhibit pseudo-plastic fracture characteristic.