Abstract: CePO₄ fluorescence nanomaterials with different crystal structures and morphology was hydrothermally synthesized and characterized with the techniques of X-ray diffraction (XRD),transmission electron microscopy (TEM),scanning electron microscopy (SEM) and fluorescence spectroscopy,etc.The effects of pH and temperature on the crystal structure,morphology and fluorescent intensity of CePO₄ were investigated.The SEM results indicated that CePO₄ prepared in acidic solution (pH=1,120℃) were nanorods,while CePO₄ prepared in alkaline solution (pH=12,120℃) were nanoparticles.The XRD results showed that CePO₄ prepared in acidic (pH=1,120℃) solution had a hexagonal crystal structure.However,the crystallinity of CePO₄ obtained in the acidic solution was better than that of CePO₄ obtained in the alkaline solution.The crystal structure of CePO₄ depended on the preparation temperature.The CePO₄ had a hexagonal crystal structure when it was prepared at 120℃ and pH=1.CePO₄ with monoclinic and hexagonal crystal structures can be simultaneously formed with increasing the preparation temperature.Only CePO₄ with the monoclinic structure was obtained when the temperature was 200℃.Fluorescence spectra indicated that both hexagonal and monoclinic CePO₄ showed a broad emission band at between 300~400 nm due to the 5d-4f emission of cerium.However,the fluorescence intensity of the monoclinic CePO₄ was stronger than that of hexagonal one.