CaSi₂N₂O₂ codoped with 2% Eu (fixed) and varying M concentrations (Gd:1% -12% ,Dy:0.25% -6%) for white LED are prepared by solid-state synthesis method. Crystalline phase is investigated by powder X-ray diffractormeter (XRD),and it is found That ,the Eu,M-codoped Ca1-ySi2N2O2 phosphors have the monoclinic structure. Excitation spectra and emission spectra are investigated by spectrometer. The results indicate that there is a broader emission band centered at 550 nm when excited by 380 nm,which was ascribed to the electronic transition of the Eu²⁺. Dy³⁺ and Gd³⁺ ions successfully play the role of sensitizer for energy transfer in the system. The addition of M remarkably enhances the luminescent intensity by the factor of 139% and 143% for Dy and Gd respectively. The luminescence mechanism of phosphors codoped with Dy³⁺ or Gd³⁺ ions is also investigated.