Abstract: CO-releasing materials are valuable for CO medicinal applications. Herein, by using an iron complex, Fe(η⁵-Cp)(CO)₂I as iron-based carbon monoxide-releasing molecule (FeCORM), cellulose acetate (CA) and polyvinylpyrrolidone (PVP) as matrix polymers, CA-PVP-based composite fibers with various amounts of FeCORM were prepared via electrospinning technology in a mixture solution of dimethylacetamide/acetone. The composite fibers were characterized by means of ATR-FTIR, UV-vis DRS, SEM techniques. CO-releasing performance of the composite fibers was then investigated upon irradiation of blue/green/red lights, and their corresponding kinetic data were obtained, respectively. The amounts of CO released by the composite fibers were further quantified. Our results demonstrate that the rates of CO-release for the composite fibers are depending on both the contents of FeCORM and the wavelengths of the light sources. Generally, the lower the content and the shorter the wavelength, the faster the release rate should be. Additionally, first-order kinetics are assigned to the CO-release process of the composite fibers, with a rate constant k_obs between 1.59-0.11 min⁻¹, and a half-life t_1/2 between 0.4-6.3 min, respectively. Furthermore, a satisfied linear-relationship is estimated between the dose of released CO for the composite fibers y and the mass percentage of FeCORM x with the equation following: y=0.0284x−0.0158.