In the present paper, AlF3-YbF3∶Er3+ was prepared by high temperature solid phase reaction, and the concentration effect of Er3+ on luminous intensity of phosphors was studied. The crystal structures of the phosphors were characterized by means of X-ray diffraction (XRD), and the upconversion luminescence properties of phosphor were studied by fluorescence emission spectra. Upon 980 nm excitation, when the Er3+ concentration was fixed to be 0.7 mol％, the maximum red emission intensities can be obtained in the sample. Furthermore, the research results showed that the fitted slope for red transition emission was 2.24, indicating that red emission is due to a two-photon excitation process.