The carbonate phosphors Sr1-x-yBayCO3:xEu(2+) (0 < x < 0.06, 0 < y < 0.67) were prepared by a modified solid-state reaction. The electronic structure of SrCO3 was calculated using the CASTEP code. The result shows that SrCO3 has an indirect energy gap of about 4.3 eV, which agrees with the experimentally determined value (about 4.4 eV). In addition, the photoluminescence properties of Eu2+-doped Sr1-xBaxCO3 (0 < x < 0.67) have been studied carefully. The phosphors Sr1-xCO3:xEu(2+) (0 < x < 0.06) show a strongly broad-band absorption in the range of 390-600 nm and emit a broad luminescence band in the range of 550-750 nm with a maximum peak at 618 nm. With the replacement of Sr2+ by Ba2+, the position of the maximum emission peak shifts from 618 to 750 nm, and the chromaticity index of Sr1-xBaxCO3:0.02Eu(2+) (0 < x < 0.67) shifts correspondingly from (0.633, 0.366) to (0.673, 0.326). Therefore, the phosphor can be well matched with the blue-emitting GaN chip to compensate the red color deficiency of commercial phosphor yttrium aluminum garnet Ce3+-based white light-emitting diodes or to create white light by combining with a blue chip and another green phosphor.