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Eu3+ doped-CdTe (CdTe∶Eu3+) nanocrystals were prepared via a facile hydrothermal method,and Eu3+ was successfully incorporated into the crystal lattice of CdTe and measured by X-ray powder diffraction (XRD),transmission electron microscopy (TEM),ultraviolet-visible (UV-Vis) absorption spectroscopy and fluorescence emission.The CdTe∶Eu3+ nanocrystals still have a cubic crystal structure,and the corresponding XRD peaks of CdTe∶Eu3+ nanocrystals shift to larger angles compared with those of pure CdTe.The CdTe∶Eu3+ nanocrystals are monodisperse and the particles size is about 2-4 nm.Compared with pure CdTe,the CdTe∶Eu3+ nanocrystals have larger band gap and thus exhibit blueshift in the emission spectra,which could be accounted for by the energy transfer between Eu3+ and CdTe.To enhance the stability and functionality of CdTe∶Eu3+ nanocrystals,the CdTe∶Eu3+ nanocrystals were coated with SiO2 and the core-shell SiO2-coated CdTe∶Eu3+ nanocrystals (CdTe∶Eu3+@SiO2) were prepared via microemulsion method.TEM results show that CdTe∶Eu3+ nanocrystals are uniformly dispersed in the shell,and CdTe∶Eu3+@SiO2 nanospheres are uniformly spherical with an average diameter of about 75 nm.The fluorescence emission of CdTe∶Eu3+@SiO2 (567 nm) shows a blueshift compared with that of CdTe∶Eu3+ nanocrystals (632 nm),possibly because of altered surface properties after SiO2 coating.CdTe∶Eu3+ and CdTe∶Eu3+@SiO2 with tunable photoluminescence are potentially useful in fabricating optical and bioimaging devices.