A foaming cement (1), cooperates with the steel member (5), forms the fender structure (111), which could solely resist the load in horizontal or vertical direction, or cooperate with the columniation (222). The whole lightweight steel (5) is embedded in the foaming cement or the floor slabs. The fender structure (111) cooperates with the roof board, the ceiling (555) and the various floor slabs (333) in forming the structural system, which is capable of preserving heat and bearing the load and beautifying the environment.