In the study, a polypropylene monofilament was used as the sheath and carbon fibers were used as the core. Carbon/PP ply yarn were braided using a braiding machine, and then light weight grids with weave structure were made from the ply yarn. We improved the framework of the weaving machine for making the grids, and controlled the tension of the ply yam in the weaving process. The strength of the single rib and junction of the grids were discussed.