Abstract: The hoop bond performance between corroded rebar and concrete was explored in this paper.The research is significant to the prediction of time when the internal cracking due to corrosion happened.Concrete strength and type of rebar was taken into account at the design of torsion specimen.In the test, constant current was used to accelerate corrosion course.Torque wrench was the loading tool.The relative angle between concrete and rebar was recorded by use of clinometer.The results indicate that the ultimate torsional bearing capacity and torsional rigidity of plain round bar are less than deformed rebar.The ring bonding shear strength is steady when the corrosion level is small for the deformed rebar.When the corrosion level reaches a certain extent, the ring bonding shear strength begins to decrease.Because of additional mechanical bite force, the hoop bonding shear strength is increased with corrosion level.When the corrosion level reaches a certain extent, the hoop bonding shear strength decreases in a smaller rate.