In this work,a series of post-processing experiments was conducted on cerium-doped yttrium aluminum garnet( YAG∶ Ce3 +) yellow phosphor in order to improve their luminescent properties. Several kinds of alkali,e. g.,ammonia,N,N-dimethylacetamide( DMAC),triethanolamine and polyacrylamide,were selected as post-processing reagents. Effect of the type,the concentration of the post-processing reagent,and the soaking on the PL intensity of YAG∶ Ce3 +were investigated in details. The optimum condition is to soak the phosphor in a 30% ammonia solution for 50 min at 50 ℃. The PL intensity of the phosphor increased about 9. 5%,and the agglomeration among particles decreased after post-process.