Abstract: Current failure criterions are mainly focused on qualitatively charcterizing the plastic deformation degree of structural members, without considering the influence of deformation ability on the degradation of performance and damage of the members. A ductile failure criterion was established on the grounds of the investigation of the correlations between ductility, axial compression ratio, stirrup ratio and structural failure of reinforced concrete (RC) frame columns. The calculation formula for the concerened damage index was proposed using the combination of statistical methods and of the Arrenius formula. According to 105 sets of low-cycle repetitive loading members and to 9 sets of monotonic loading members, under 4 different conditions, it can be drawn that the calculated damage indexes were all about 1.0 with standard deviations between 0.2 and 0.4. The above results indicate that the proposed ductile criterion can well quantitatively characterize the ductile damage of RC columns. Moreover, in the case of considering stirrup ratio and degradation of bearing capacity of RC columns, the calculated damage index also can well reflect the damge of the members. The damage evaluating standards of ductility criterion for RC columns were proposed based on the comprehensive consideration of the experimental phenomena, of damage characteristics and of the calculated damage index of 29 columns. The work can provide a reference for the damage evaluation of RC columns.