Abstract: As a permanent implantable medical material and pharmaceutical formulation component，Polyvinyl alcohol （PVA） has a wide range of applications.In this work，water was used as the only medium to successfully prepare a composite fluorescent hydrogel of PVA，carboxymethyl cellulose （CMC） and carboxymethyl cellulose/rare earth complex （CMC/Eu，i.e.CE） by a freeze-thaw cycle method.The morphology and structure of the hydrogels were characterized by SEM and FT-IR.The results show that hydrogen bonding and other interactions occurred among CE，CMC and PVA to form multi-pore structure.DSC and XRD results show that the crystal structure of PVA is retained in the hydrogel after the addition of CMC，but the crystallinity decreases.The improvement of the mechanical properties of these hydrogels is due to the hydrogen bonding of the hydroxyl in CE，CMC and PVA molecules as well as other interactions between molecular chains，which improve the fusion between molecular chains and enhance the bonding strength among various components.Especially，when the mass ratio of CMC to PVA is 1：5，its tensile modulus of elasticity can reach 39.86kPa，and the compressive modulus of elasticity can reach to 273.31kPa.Photoluminescence （PL） results show that the PVA/CMC/CE hydrogel has the 5D0→7F2 characteristic emission peak of Eu3+ near 635nm when the excitation wavelength is 394nm.It displays red fluorescence under ultraviolet light，indicating that the hydrogel has a basis for potential applications in fluorescent probes，anti-counterfeiting and biomarkers.

Key words: carboxymethyl cellulose/rare earth complex, carboxymethyl cellulose, polyvinyl alcohol, hydrogel, fluorescence property, mechanical property