A novel green light-emitting phosphor Sr3Y(PO4)3Ce3+,Tb3+ was synthesized by the traditional high temperature solid state reaction method.Luminescence mechanism and crystal structure were investigated by X-Ray Diffraction (XRD) and photoluminescence spectra (PL).The XRD patterns demonstrate that the samples belong to the single phase of Sr3Y(PO4)3 in experimental doping concentrations range.Obviously,the excitation band of Sr3Y(PO4)3∶Tb3+ and the emission of Sr3Y(PO4)3∶Ce3+ have a significant spectral overlap in the wavelength range of 330~380 nm,which implies the great possibility of an efficient ET from Ce3+ to Tb3+.Under the 315 nm ultraviolet excitation,a blue emission(320~420 nm)from Ce3+ and a yellowish-green emission(480~500,530~560 nm)from Tb3+ were obtained from Sr3Y(PO4)3∶Ce3+,Tb3+.When the Ce3+ concentration was 7%,the emission could be adjusted from blue to green region by tuning the Tb3+ doping concentrations from 1% to 50% through an energy transfer process.This text plot the schematic energy levels of Ce3+,and Tb3+ with electronic transitions and energy transfer processes in Sr3Y(PO4)3∶Ce3+,Tb3+,which disclose the electron motion processes of Sr3Y(PO4)3∶Ce3+,Tb3+.From the dependence of relative emission intensity of Ce3+,Tb3+ (5D4→7Fj)and ET efficiency from Ce3+ to Tb3+ on the concentrations of Tb3+,It can be seen that the relative intensity of Tb3+ and the values of ηET increase gradually with the increasing of Tb3+ as well as the relative intensity of Ce3+ decreases remarkably.The largest energy transfer efficiency reaches as high as 80% when the concentration of Tb3+ was 50%,demonstrating the efficient energy transfer from Ce3+ to Tb3+.The CIE chromaticity coordinate positions are plotted,as can be seen the emitting color of Ce3+ and Tb3+ singly doped Sr3Y(PO4)3∶Ce3+,Tb3+ phosphor are blue and yellowish green,respectively.The emitting color of samples Sr3Y(PO4)3∶Ce3+,Tb3+ changes from blue region to green region with the rising doping contents of Tb3+.Sr3Y(PO4)3∶Ce3+ and Tb3+ phosphor can be used as a green light-emitting phosphor in white LED devices and LCD backlights.