GFRP(Glass Fiber Reinforced Plastics) used for the large scale wind turbine blade are required the high material strength and formability. The strength is improved by the addition of short fibers which distributes randomly in GFRP. However, the addition causes the decrease of the resign fluidity in molding by RTM (Resin Transfer Molding) method. In this study, the relationship between tensile, fatigue strength and the fluidity of GFRP by the addition of short fibers are examined.