Abstract: Angle-ply of±45°_8s unidirectional glass fiber reinforced epoxy composites were made by vacuum assisted molding process. The shear properties under constant strain rate were researched by special equipment. Test strain rate was from 3×10^-4 s^-1 to 128.4 s^-1. A shear rate-dependent constitutive model of unidirectional glass fiber reinforced epoxy composite under intermediate strain rate was established based on Khan-Huang model. The optimal parameters were identified by least square method and genetic algorithm. The results show shear properties of unidirectional glass fiber reinforced epoxy composite depends on strain rate and shear strength increases with strain rate. The ultimate strength increases by 35.5% at 128.4 s^-1. Constitutive model established in this paper can accurately reflect the shear properties of unidirectional glass fiber composite, and can be used to predict shear properties under intermediate strain rate.