The mechanical behavior of three dimensional glass fabric reinforced composites, named Parabeam 3D composites, with two plain woven fabrics and vertical yarns were investigated by compressive and 4-point flexural tests. The main advantage of 3D glass fabric reinforced composites is that the pile threads in the core bind the facesheets together, thus are able to hinder the delamination between layers. Both the compressive strength and flexural strength of 3D glass fabric reinforced composites were inversely proportional to a square of the thickness of 3D glass fabric reinforced composites. The compressive strengths decreased from 12.0MPa to 2.7MPa with increasing the thickness of 3D glass fabric reinforced composites from 3.2mm to 8.2mm. The flexural strengths decreased from 25.2MPa to 3.8MPa in warp direction and decreased from 27.5MPa to 5.0MPa in weft direction with increasing the thicknesses of 3D glass fabric reinforced composites from 3.2mm to 8.2mm. The flexural strength in weft direction was 30% higher than that in warp direction showing anisotropic mechanical behavior due to a larger number of vertical yarns in weft direction.