To study the failure behavior of carbon fiber composites in simulated acid rain,electrochemical impedance spectroscopy(EIS)was employed to study the failure behavior of carbon fiber composites in stimulated acid rain.The mechanical properties were tested by universal testing machine.The failure mechanism was analyzed by FT-IR and XPS.SEM showed the cross sectional microstructure of composites.The results show that the EIS could distinctly reflect the failure behavior under full-time immersion and constant p...