The three-dimensional orthogonal M40 J/Al composites with 50%（volume fraction） fiber were prepared by vacuum pressure infiltration with ZL301 alloy as the matrix and perform made of M40 J carbon fiber woven into three-dimensional orthogonal structure. The microstructure and fracture morphology of the composites were analyzed by SEM. The effects of notch position on the longitudinal tensile properties of the three-dimensional orthogonal M40 J/Al composites were investigated

and the failure mechanism was discussed. The results indicate that the tensile strengths of the composites with V-notch

rectangular notch and central circular hole notch at room temperature are 690.7、667.0 and 314.2 MPa

respectively

which are 9.24%

12.35% and 58.71% lower than those of the unnotched specimens（761.0 MPa）. The internal notch has the greatest effect on the tensile properties of M40 J/Al composites with three-dimensional orthogonal woven structure compared to the external notch. The fracture location of composites containing the central circular hole notch is concentrated at the notch

which is extremely sensitive to the central circular hole notch with the lowest tensile strength compared to the other three types of composites.