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以氟化钠和稀土硝酸盐为原料，柠檬酸钠为表面活性剂，采用水热法制备出微米级NaYF4∶Yb3＋， Er3＋上转换发光材料。通过X射线衍射（XRD）、扫描电子显微镜（SEM ）和荧光光谱仪对所制备样品的晶相、形貌和发光特性进行了研究。结果表明，通过调节NaF／RE3＋的比例（5，6，7，8，9，11），实现了样品从立方相到六方相的转变，样品的立方相和六方相的X射线衍射峰分别与标准卡片 PDF＃77-2042和PDF＃16-0334完全匹配。由扫描电镜图可以看出，样品的结晶度高，分散性好，形貌从棒状转变为六边形片状。样品的上转换荧光光谱显示，随着NaF／RE3＋的比例增大，样品的红绿光发射峰均增强，样品的520和539 nm处的绿光发射峰对应的是Er3＋的2 H11／2→4 I15／2和4 S3／2→4 I15／2的能级跃迁，而653 nm处的红光发射峰对应的是Er3＋的4 F9／2→4 I15／2的能级跃迁。由样品的色度坐标图得出，调节NaF／RE3＋的比例还可以实现样品的光色可调，随着NaF／RE3＋的比例增大，样品的整体发光光色实现了从黄光区到近红光区的移动。由上述结果可以得出，通过相对简单的实验方法，温和的实验条件和相对低廉的材料成本，仅通过改变原材料中单一组分（NaF）物质的量，就达到了样品NaYF4∶Yb3＋，Er3＋晶相、形貌转变以及发光光色移动的良好控制。荧光材料的晶相和形貌对其上转换发光的影响在光子器件和生物分析的研究中具有重要的潜在应用。“,”Using sodium fluoride and rare earth nitrate as raw materials and sodium citrate as surfactant ,micron grade NaYF4 upconversion luminescent materials were prepared by hydrothermal method .By X-ray diffraction(XRD) ,scanning electron mi-croscope(SEM ) and fluorescence spectrometer ,the crystal phase ,morphology and luminescent characteristics of the prepared samples were investigated .The results showed that the phase of the samples could generate a transition from cubic phase to hex-agonal phase by adjusting the proportion (5 ,6 ,7 ,8 ,9 ,11) of NaF/RE3+ ,and the X ray diffraction peaks for the cubic and hexagonal phase of samples exactly matched with those of the standard card of PDF #77-2042 and PDF#16-0334 ,respectively . The SEM photographs showed that the crystallinity of samples was high and the dispersibility was favourable ,the morphology were translated from microrods to hexagonal microplates .The samples upconversion luminescent spectra showed the intensity enhancement of red and green light emission peaks with increasement of the ratio of NaF/RE3+ .The green emission peaks of samples at 520 and 539 nm corresponded to the 2 H11/2 → 4 I15/2 and 4 S3/2 → 4 I15/2 level transition of Er3+ ion ,and the red light emission peaks of samples at 653 nm corresponded to the 4 F9/2 → 4 I15/2 levelt ransition of Er3+ ion .The chromaticity coordinate di-agram exhibited that the change of the luminescent color of samples could be achieved by adjusting the ratio of NaF /RE3+ .With the increasing of NaF/RE3+ ratio ,for the whole light-emitting colors of samples ,the shift from yellow region to near red region could be realized .It can be concluded that through the relatively simple experimental procedure and lower cost materials ,the change of phase and morphology ,the moving of light-emitting color for sample NaYF4 ∶Yb3+ ,Er3+ could be well controlled on-ly by changing the single component (NaF) molar ratio in the raw materials .The effect of phase and morphology of fluorescent materials on their upconversion luminescence has great potential applications in photonic devices and bioanalysis research .