The present invention provides a glass fiber composition, a glass fiber and a composite material therefrom. The glass fiber composition comprises the following components expressed as percentage by weight: 58-64% SiO2, 14-19% Al203, ≧8.8% and <11.8% CaO, 7.5-11% MgO, 0.2-2.7% SrO, 0.1-2% Na2O+K2O, 0.05-0.9% Li2O, 0.05-1% Fe2O3, 0.05-1.1% TiO2 and <0.5% F2, wherein the range of the weight percentage ratio C1=(MgO+SrO) / CaO is 0.75-1.1, and the range of the weight percentage ratio C2=CaO / MgO is less than 1.4. Said composition can effectively inhibit the crystallization tendency of glass, significantly decrease the liquidus temperature and crystallization degree of glass and also has an outstanding glass refractive index and outstanding modulus.