Controlling the corrosion rate is critical for practical applications of Mg-based alloys.In this work,we constructed a protective coating of hybrid polycaprolactone(H-PCL)/indocyanine green(ICG)on AZ31 Mg alloy,whose degradation rate was controlled by 808-nm near-infrared(NIR)light irradiation.The corrosion behaviors of H-PCL/ICG coated Mg alloys were systematically inves-tigated by potentiodynamic polarization tests,electro-chemical impedance spectroscopy(EIS)and hydrogen evolution experiments.The results disclosed that the H-PCL/ICG composite coating could effectively protect Mg alloy from corroding without NIR light irradiation.In contrast,under 808-nm NIR light irradiation,the corrosion resistance of this composite coating was decreased significantly,i.e.,the corrosion current density(icorr)increased from(8.81±1.068)×10-8 to(1.22±0.545)×10-6 A·cmr-2.This is because the component of ICG in the coating was excited to produce heat locally,which triggered the glass transition tempera-ture(Tg)of H-PCL in the coating,resulting in the motion of the molecular chain segment.Consequently,the elec-trolytes penetrated the coating and corroded the Mg sub-strate.In vitro biological experiment indicated that the synthesized coating exhibited good cytocompatibility.Hence,these findings will provide a new strategy for designing novel photoresponsive coatings to remotely adjust the degradation rate of biodegradable metals for biomedical applications.