Abstract: In order to investigate the effect of corrosion on the surface properties of steel plate and interfacial bonding properties between CFRP plate and corroded steel plate, surface characteristic test of corroded steel plates with six kinds of corrosion duration and tensile test of thirty-four double-lap specimens with CFRP plates and corroded steel plates were carried out. The effects of corrosion duration on the morphology and surface roughness, apparent contact angle and surface free energy of steel plate, and the failure mode, effective bond length and ultimate load of bonding interface between CFRP plate and corroded steel plate were revealed. Test results show that with the increase of corrosion duration, pitting corrosion and uniform corrosion alternately play the dominant role on the surface topography, the surface roughness and surface free energy of the corroded steel plates fluctuate up and down continuously. The failure mode of bonding interface between CFRP plate and corroded steel plate is mainly the mixed of steel/adhesive interfacial debonding and CFRP/adhesive interfacial debonding, and the corrosion duration only has a certain influence on the area proportion of the mixed failure type. As for the specimens with the si-milar adhesive thickness, the effective bond length of the corroded specimens is significantly larger than that of the un-corroded ones, the effective bond length for the specimens with the corrosion duration of 0-12 months and the adhesive thickness of 0.21-0.7 mm are approximately 63.75-91.5 mm. With the increase of corrosion duration, the ultimate bearing capacity of the bonding interface increases at first and tends to be stable afterwards, the increase of surface area, surface free energy and surface roughness caused by corrosion plays the favorable factor on the ultimate bearing capacity.