This paper study discussed the applicability of Park-Ang model modified by Wang based on the pseudo-static test results of reinforced concrete columns. The structural damage index based on the component level was selected, and both the incremental dynamic analysis and fragility analysis of the reinforced concrete frame were conducted. Additionally, the prediction by the modified method to evaluate the seismic performance in terms of the damage index of the RC frame was compared with the maximum inter-story drift ratio of the fragility analysis result. The analysis results show that the modified Park-Ang model that considers the loading path effect predicts well the cumulative damage process after the first damage, which discriminates the specimen damage status accurately, the damage development process, and the overall and local failure mechanism. Further, the weak links can be accurately distinguished. However, the damage index higher than 1.0 may be caused by using these methods, which cannot accurately reflect the basic meaning of the original definition. Compared with the maximum inter-story drift ratio, the seismic performance evaluation method using the damage index considers the structural response and properties. The modified method can be used to evaluate the structural performance more comprehensively and predict the failure probability of the structures under different earthquake loads.