Asphalt aging is inevitable to the asphalt pavement performance, which will lead asphalt to hardening gradually and becoming brittle. Therefore, aging progress shortens the life of asphalt, but the study on polymer asphalt improves the phenomenon. The present situation on aging of polymer modified asphalt is summarized and the aging mechanism of modified asphalts is analyzed in the paper. Otherwise, the research progress at home and abroad on the aging properties of modified asphalt is introduced by a series of characterization techniques, which include mechanics technique, rheology technique, FTIR, GPC and so on