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CaWO4 phosphor activated by the Tm3+/Yb3+,Er3+/Yb3+ and Ho3+/Yb3+ ions were synthesized by a traditional high-temperature solid-state method.The crystal structures and morphologies of the products were characterized by X-ray powders diffraction method (XRD),infrared spectra (FT-IR) and scanning electron microscopy (SEM).The samples were found to show up-conversion luminescence properties.CaWO4 doped with Tm3+/Yb3+ showed blue luminescence characteristic of Tm(Ⅲ) ion in the range of 460-485 nm,corresponding to the 1G4→3H6 electronic transition.CaWO4 doped with Er3+/Yb3+ showed strong green luminescence at 510-565 nm (2H11/2,4S3/2→4I15/2) and weak red luminescence at 640-685 nm (4F9/2→4I15/2) of Er(Ⅲ) ion.CaWO4 doped with Ho3+/Yb3+ phosphor emitted green luminescence at 525-560 nm (5S2,5F4→5I8) and red luminescence at 630-670 um (5F5→5I8) and at 730-770 nm (5S2,5F4→5I7),which is the characteristic of Ho(Ⅲ) ion.