Ca2MgSi2O7∶Ce3+,Tb3+ phosphors were prepared by the sol-gel method, and their structure and optical properties were studied by X-ray diffraction (XRD), fluorescence spectrophotometer, differential termal analysis (DTA) and transmission electron microscopy (TEM) respectively. Excited at the near ultra-violet 331nm light, the emission band consists of five peaks located at 382, 485, 544, 584, 619 nm respectively. The white light can be obtained by mixing the five emission peaks in the single host. Energy transfer exists between Ce3+ and Tb3+, and the energy transfers from the Ce3+ sensitizer to the Tb3+ activator. The emission color can be changed by tuning the concentration of the Ce3+ and Tb3+ in the Ca2MgSi2O7∶Ce3+, Tb3+ phosphors. When the concentration of the Ce3+ and Tb3+ are 0.01 and 0.05 respecttively, the chromaticity coordinate of the phosphor is measured to be (0.31, 0.37), which is close to the coordinate of standard pure white (0.33,0.33). Ca2MgSi2O7∶0.01Ce, 0.05Tb phosphor is a promising single-phased white-light emitting phosphor.