CaCO3:RE3+(RE=Eu, Tb, Ce) phosphors were synthesized via a microwave co-precipitation method. The luminescence-tunable composite of CaCO3:RE3+/PP (polypropylene) was prepared by a melt blending method. The photoluminescence and mechanical properties of the composites were characterized by photoluminescence excitation and emission spectroscopy, chromaticity coordinates, scanning electronic microscopy and X-ray powder diffraction, respectively. The results show that the phosphors have a good compatibility with PP. When 5% (in mass fraction) CaCO3:RE3+ is incorporated into PP, the mechanical and photoluminescence properties of composite are preferable. In addition, CaCO3:Eu3+/PP emits a red color, CaCO3:Tb3+/PP emits a green color and CaCO3:Ce3+/PP emits a purple color under the ultraviolet light, and the emitting color of composites can be shifted among red, green and purple region by altering the ratio of phosphors or excitation wavelength. © 2016, Editorial Department of Journal of the Chinese Ceramic Society. All right reserved.