This paper seeks to provide a comprehensive review of PEM fuel cell degradation mechanisms under typical automotive operating conditions, including open-circuit/idling, dynamic load,and startup-shutdown. The AST method, performance degradation characteristics, and decay of key parameters are all analyzed. Time dependent changes in components, microstructure, and morphology under typical operating conditions are highlighted. Some controversies in durability research are also discussed. This paper provides a fundamental basis for designing a the highly-durable MEA,and guides the optimization of operating conditions of an automotive fuel cell to retard the aging process and prolong lifetime.