A long glass reinforced resin composite of the present invention may comprise two kinds of thermoplastic matrix resin (a1, a2) which have different viscosities and a long glass fiber (B). The method of preparing the long glass reinforced resin composite comprises preparing a LFT (Long fiber thermoplastic) master-batch composition by impregnating the long glass fiber (B) of continuous phase into the low viscosity thermoplastic resin (a2), and compounding the LFT (Long fiber thermoplastic) master-hatch composition with high viscosity thermoplastic resin. The long glass fiber reinforced resin composite of the present invention has excellent mechanical properties such as impact strength, tensile strength, and flexural modulus.