Abstract: To evaluate the applicability of the endurance time analysis（ETA） in the seismic performance evaluation of asphalt concrete core sand-gravel（ACCSG） dams, this study selects ten records of measured ground motions for incremental dynamic analysis（IDA）, and compares the acceleration, dynamic displacement, and relative dam crest settlement ratio for different ground motion intensities. We use a typical 100 m level ACCSG dam as the study case and four endurance time acceleration curves（ETAC）synthesized through optimizing target response spectra as the ground motion inputs. The results show that ETA better predicts the dynamic dam responses to different seismic intensities, and its calculations fall in the enhanced dynamic analysis envelope. The calculated seismic responses feature a narrow scatter range,verifying that ETA can avoid multiple calculations for amplitude modulation and improve computational efficiency and accuracy, and that it is a more efficient and feasible new method for seismic performance assessment of the ACCSG dams in Western China.