Abstract: In order to obtain hot structure composites with high performances, a series of two-dimensional carbon/carbon composites was prepared with the domestic T300 carbon fiber as raw material by carbon cloth prepreg layer alternating ply hot pressing and liquid impregnation pyrolysis method, and the microstructure features, mechanical properties and ablation properties of two dimensional carbon/carbon composites were characterized and discussed. The investigation results show that the types of carbon cloth and preparation process have obvious effects on the mechanical properties of two dimensional carbon/carbon composites. When the type of carbon cloth selects eight heddle satin, after carbonization pre-treatment and the temperature of high temperature treatment reaches 2 300℃, the highest values of tensile strength and interlaminar shear strength for two dimensional carbon/carbon composites reach 301 MPa and 12.4 MPa respectively, which reach the international advanced level. The ablation properties for different two dimensional carbon/carbon composites are almost the same under the simulated inspection status of typical service condition. None of them has the ablation peeling off phenomenon due to the low interlaminar strength, showing good ablation uniformity and structural reliability.