Abstract. The red-emitting phosphor Sr2CeO4: Eu3+, Sm3+ was synthesized by conventional high-temperature solid-state method. X-ray diffraction, and photoluminescence spectra were used to characterize the as-synthesized phosphor. In Eu3+ singly doped Sr2CeO4 phosphors, Eu3+ ion showed a weaker 7F0-5L6 transition at 395 nm with a narrow line and could not be efficiently excited by the NUV-LED chip. In Sm3+, Eu3+ co-doped Sr2CeO4 phosphors, the energy transfer from Sm3+ to Eu3+ in Sr2CeO4 host is observed and investigated in detail. The absorption band around 404nm was broadened and the intensities of the main emission line (5D0→7F2 transition of Eu3+ at 614nm) were strengthened because the energy transfer from Sm3+ to Eu3+. Moreover, The chromaticity coordinates of Sr2CeO4: Sm3+ can be regulated to approach the NTSC standard values of red phosphor by codoping Eu3+ ions. The photoluminescence properties suggest that novel Sr2CeO4: Eu3+, Sm3+ phosphor might have a potential research value on white-LEDs.