Abstract: The mixed reinforcement combining bias stitching and Z---pin inserting was used to prepare foam core sandwich structures. The prepared sandwich structures were tested under flatwise compressive, flatwise tensile and shear loads, and the mechanical properties and damage modes were also studied. The results indicate that the compressive strength and modulus are improved with increasing Z---pin inserting, while the tensile strength, modulus and shear strength are improved with increasing bias stitching. However, there is no significant distinction in the shear modulus between different specimens.