<p>In recent years, the application of carbon fiber reinforced plastics (CFRP) to aircraft has been expanding to reduce the weight of aircraft. Furthermore, the weight of the aircraft can be further reduced by replacing mechanical fastening with adhesive bonding. In this study, we aim to investigate the effect of galvanic corrosion on the mechanical properties of aluminum-CFRP adhesive joints. Adhesive joint specimens with salt spray treatment and untreated references were prepared. Tensile shear adhesive strength and failure mode of the joints were evaluated by performing tensile shear tests on specimens and observing the fracture surfaces after the test. In dissimilar material adhesive joints under salt spray, galvanic corrosion of the aluminum substrate occurred within 24 hours, and the adhesive-adherend interfacial strength decreased significantly compared to similar material adhesive joints. In addition, the failure mode of dissimilar material adhesive joints changed from mixed failure of interfacial failure and fiber tear failure to interfacial failure.</p>