Abstract: The tensile mechanical properties of two dimensional C/SiC composites at 4 strain rates (0.001, 0.010, 90.000 and 350.000 s^-1) were investigated by split Hopkinson tensile bar device and an electronic universal test machine. The stress equilibrium status in the dynamic experiment was calculated and verified. SEM was employed to analyze the damage fracture and failure mechanism of the composites at different strain rates. The damage and strain rate related constitutive equation of the composites was established. The results show that the stress-strain curves of the two dimensional C/SiC composites show non-linearity characteristics. The tensile strength increases from 204 MPa to 270 MPa, up by 33% with the increase of strain rate for two dimensional C/SiC composites, testifying the strong strain rate sensitivity of the tensile strength for the composites. The composites show different failure modes under quasi-static and dynamic loading, which are caused by the strain rate effect on the interface behavior in the material.