In order to obtain a long-wavelength red phosphor,the phosphor Ca 0.5－xSr0.5MoO₄:xSm³⁺ un der the UV excitation was synthesized by solid state reaction in our work.The luminescent properties and crystal structure are studied.X-ray diffraction (XRD) results show that the crystal phases of these samples agrees well w ith the crystal phase of host Ca0.5Sr0.5MoO₄.Its excitation spectrum has a broad band and several sharp peaks.Through the analys is of the emission under different excitation wavelength and the cooperation with Ca0.5Sr0.5MoO₄:Eu³⁺,we could conclude t hat the broad band is the most effective excitation band,which can be attributed to Mo⁶⁺－O2－ charge transfer transition.Under the exc itation of 275nm,the emission spectra of the Ca0.5－xSr0.5MoO₄:xSm³⁺ phosphors are composed of four major emi ssion peaks centered at 564nm(⁴G5/2→⁶H5/2), 606nm(⁴G5/2→⁶H7/2),647nm(4G5/2→⁶H9/2) and 707nm(⁴G5/2→⁶H11/2),and the strongest peak appears at 647nm as red emission.The concentration q uenching happens when the concentration of Sm³⁺ is 6%.Analysis shows that the concentration quenching mechanism is the energy transition among the nearest neighbor ions.At the same time,the charge compensator,such as Li⁺,Na⁺,K⁺ and Cl－ can en hance the emission intensity of the Ca0.5－xSr 0.5MoO₄:xSm³⁺ phosphors,and the doping Na + charge compensator has the most obvious effect.