The pace of Arctic warming is about double that at lower latitudes in the recent decades,a robust phenomenon known as Arctic Amplification(AA),which has become one of the most notable features of climate change. This review summarized the major advances of the mechanism of AA from both local factors and poleward heat transport from lower latitudes. Local factors, including positive ice-albedo feedback and increasing downwelling longwave radiation caused by water vapor and cloud,play an important role in AA. Due to the colder background temperatures and the more stable vertical structure than the lower latitudes,the temperature feedback is therefore positive,which induces the warm signal amplified in the Arctic. The poleward heat transport via atmosphere circulation and ocean currents is also a contributor to AA,and the multidecadal variability in the Pacific,the Atlantic and the tropical Pacific surface temperature are the dominant forcing of the atmosphere circulation. Finally,several issues that remain to be solved were proposed.