Abstract: The tensile properties in warp and weft directions of four different st ructural kinds of carbon/ resin 3Dwoven composites are evaluated based on a series of experiment comparison and analysis. The result s indicate thatthe load-displacement curves of the four kinds of 3D woven composites in both directions show double linearity , andthe initial module is higher than the second module ; there is no yield point st rength at load-displacement curves of allkinds of 3D woven composites , which shows that the composites are brittle material ; 3D woven composites providegood mechanical behavior , and achieve higher tensile properties in both directions for one st ructural kind of composites ; the function of warp-stuffer is increasing the tensile st rength and module in the warp direction greatly , and thepurpose of increasing wef t density is increasing the tensile st rength and module in the wef t direction ; the compositeswith warp-stuffer and wef t-stuffer possesses the best mechanical properties among the four different st ructural kindsof 3D woven composites.