Fiber Reinforced Polymers (FRP) is a new composite material with characteristic of high tensile strength, light weight and perfect resistance to corrosion. Therefore, it is a perfect reinforcing material. To make good use of FRP, its mechanics need to be severely studied. We study the mechanics of FRP by means of experiment. The Yong’s modulus and the ultimate tensile strength of GFRP, which will be used in a bridge, are measured.