A study of the effect of air corona plasma treatment on the surface of GFRP (glass-fiber reinforced polymers) has been carried out. The aim is to alter the surface in a manner and scale resulting in stronger shear strength between GFRP and wood. The specimens are exposed to air corona discharge with the irradiation time and power being variables. Goniometry is employed to determine the contact angle of GFRP surface. The results show that the plasma treatment leads to the surface contact angle decreasing significantly. The shear strength of shear test specimens using isocyanate adhesive is stronger than that of specimens using epoxy adhesive. The interface of the GFRP-wood composites is also studied by using Fourier transform infrared spectroscopic (FTIR).