Abstract: Experiments and finite element analysis were carried out for the problem of open hole sensitivity of 3D carbon/carbon composite material plates.Finite element models of the representative volume element (RVE),the intact plate and open-hole plates of 3D carbon/carbon composite were established.Transition method between macro level stress and meso level stress was given and numerical simulation on the tensile failure of the intact plate and open-hole plates was implemented based on this method.By uniaxial tensile tests of 3D carbon/carbon composite intact plates and open-hole plates,good agreement between numerical results and experiments was observed.In addition,the influence of width to diameter ratio (WTDR) on the tensile strength was analyzed.The results show that the tensile strength of open-hole plate decreases by 11.5% comparing with that of intact plate when the WTDR reaches 6.It can be considered that the open hole makes little influence on the tensile strength of plates if the WTDR is not less than 6.And the result of the investigation provides insight into the design of carbon/carbon composite open-hole plate.