Performance based seismic design need to define the structural damage quantitatively and many scholars have presented some related damage evaluation models.Park-Ang seismic damage model is the most representative one , it considered the earthquake damage as the result of the first time of displacement exceeding and the cumulative hysteretic energy, and has a good experimental basis.By multiplying another energy weighted coefficient which is related to load path and can be calculated by critical ductility factor and equivalent energy factor, the modified Park-Ang seismic damage model is obtained for the seismic estimation of the reinforced concrete columns.In this model the critical ductility factor is calculated by the simplified equivalent plastic hinge model and is determined by the critical curvature ductility factor, this mean the proposed damage model takes into account members response quantities and seismic damage mechanism.