This study investigates the effect of surface treatment on the shear strength between aluminum panel and composite plate. The aluminum panel was surface-treated by DC Plasma and the composite Plate was surface-treated by ion beam. Lap shear test and T-peel test were performed to determine the shear strength and T-peel strength. Results showed that the shear strength of surface-treated case was 2.5 times higher than that of untreated case. The T-peel strength of treated case was more than 5 times higher than that of untreated case. SEM examination showed that the strength increase of surface-treated case was due to the more spread of epoxy to the panel.