Abstract: Objective: To prepare and characterize carboxylated polyamidoamine/ amorphous calcium magne-sium phosphate nanocomposite(PAMAM-COOH/ACMP)and preliminarily explore the ability to induce the rem-ineralization of human dentine collagen fibers.Methods: PAMAM-COOH/ACMP was prepared in aqueous solu-tion and characterized by Fourier transform infrared spectrometer (FTIR), transmission electron microscope(TEM), selected area electron diffraction(SAED)and energy dispersive X-ray spectroscopy mapping(EDX-Map-ping), respectively and the chemical structure, morphology, phase and element distribution were obtained succes-sively.In the biomimetic condition, PAMAM-COOH/ACMP was used to induce the remineralization of complete-ly demineralized human dentin collagen fiber model, and FTIR, X-ray diffraction (XRD) and scanning electron microscope(SEM)were applied to evaluate the remineralization effect.Results: The results of FTIR showed that there were phosphate groups, carbon-nitrogen bonds and amide bonds in PAMAM-COOH/ACMP.The re-sults of TEM, EDX and SEAD showed that PAMAM-COOH/ACMP was a quasi-circular amorphous nanocom-posite with a diameter of 60-90 nm, and calcium, phosphorus and magnesium elements were concentrated in the nanocomposite.SEM images indicated no large deposits of minerals on the dentin surface.However, at high mag-nification, in the groups treated with 5 mg/mL and 10 mg/mL PAMAM-COOH/ACMP, continuous minerals were observed to encapsulate the collagen fibers and narrow the gap between fibers.According to the XRD and FTIR results, these newly generated minerals were found to be calcium phosphate deposits.Conclusion: PAMAM-COOH/ACMP nanocomposite was prepared successfully and it has good dimensional stability at room tempera-ture and has the ability to accurately induce the remineralization of human dentin collagen fibers.