In this study, the repairability of RC members is expressed by the rate of increase in repair time with the increase in deformation, and the performance of suppressing the deformation is expressed by the stiffness. Using the repairability and stiffness, “Time Stiffness” which is an index expressing the damage-resistant performance of RC members was defined. This study evaluates the damage-resistant performance of RC columns with wing walls using this index, and discusses its effectiveness as an index to express the performance of suppressing repair time of RC members.