Abstract: The mechanical characteristics of the foam filled 3-D spacer fabric composites under flatwise compressive，shear and three points flexural loads were compared with 3-D spacer fabric composites and foam sandwich composites，and the effects of pile height and foam density on the mechanical properties were investigated.The results indicate that there are synergy effects between pile and foam under flatwise compressive strength and fabric piles fractured under flatwise compression. The flatwise compressive and shear strength decrease with increasing of the pile height. The flatwise compressive strength increases as exponent with increasing of the foam density.