The effect of water to cement ratio, fiber types and content, cement types on the bending performance of the extruded fiber reinforced cementitious board were studied. And it was found that polyvinyl alcohol (PVA) fibers can significantly improve the ductility of the board compared with polypropylene (PP) fibers. As PVA fiber content achieved 1.7%, the strain hardening and multiple cracking were occurred on the extruded board, while strainsoftening were shown on PP fiber reinforced cement board. The difference between the two kinds of board was from the differences of the mechanical properties of the two fibers. In addition, taking the fiber reinforced extruded board as base, the ultimate bending strength, as well as and the corresponded deflection and the resistant to chloride iron penetrating, was improved for a composite beam with fiber board and concrete compared with those of traditional concrete beam.