(Y0.95Ln0.01Ce0.04)3 Al5O12 phosphors were synthesized by high-temperature solid state reaction under reducing atmosphere and the doping effects of lanthanide ions (Ln3+) on the luminescence properties of phosphors were studied. YAG:Ce, Ln spectra of excitation and emission show that the influence between Ce and Ln3+ can be divided into the following three types: (1) The Ce3+ emission intensities are decreased slightly in the YAG:Ce doped with La3+, Gd3+ and Lu3+, respectively. (2) Because of the energy transfer and competitive absorption, for Pr3+, Sm3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+ co-doped YAG:Ce, the Ce emission intensities are observably decreased. In the YAG:Ce, Pr system, the emission of Pr3+ is at 609 nm: and in the YAG:Ce, Sm system, the emission of Sm3+ is at 616 nm. So it can increase the color rendering index (CRI) of YAG:Ce doped with Pr3+ or Sm3+. (3) It was found that doping with Eu3+, Yb3+ and Nd3+ in YAG:Ce the Ce3+ emission intensities quenched strongly.