Abstract: The pervasiveness of microplastics that can adsorb organic pollutants may aggravate the contamination in the aqueous environment. In this study, three kinds of microplastics, polylactic acid (PLA), polyethylene terephthalate (PET) and polypropylene (PP), were aged by persulfate oxidation to investigate the effect of aging on the adsorption behavior of tetracycline. The results showed that there were a lot of wrinkles, fragments and gullies on the surface of the three microplastics after aging. At the same time, the specific surface area and oxygen functional groups were increased significantly. The adsorption data were well fitted by the pseudo-first-order kinetics for original PET and PP and the pseudo-second-order kinetics for PLA, aging PET and PP. The adsorption data were in accordance with the Langmuir isotherm and dominated by monomolecular layer adsorption reactions for PLA and PET, while aging PP adsorption was more in line with Freundlich adsorption. The fitting results showed that the maximum apparent adsorption capacity (q_max) PLA and PET for TC increased to 2.293 mg/g and 3.617 mg/g respectively after aging. In addition, pH had a great effect on the adsorption capacity of microplastics, and the adsorption values of PP for TC could reach 1.214 mg/g when pH=7. Therefore, microplastics can act as effective carriers of TC, and the carrier effect of aged microplastics may aggravate the toxic effect of migration to water bodies.