A highly filled wood-plastic composite member and its production has become currently an important address of research concerned with environmental issues and engineering application of structures. Since the property of the composite material is manly depend on the wood content rate, a combination of compound, production order and so on, an investigation of production order and strength of the unit member in order to used in structures and building is important. In this paper, production and unitification of highly filled extrusion wood-plastic composite member are deal with. And also the flexural rigidity of the unit member is explained.