White　light　emitting　diodes　(LED)　are　packaged　based　on　blue　LED　dies　surrounded　by　two　different　phosphors　that　emit　red　and　green　light　respectively.　First,　the　ratio　of　two　phosphors　maintains　invariable,　color　rendering　index　achieves　the　maximal　value　in　some　color　temperature,　when　it　increases　from　2700　K　to　13000　K　by　degrees.　Then,　the　ratio　of　two　phosphors　is　changed　gradually,　by　repeating　above　test,　it　is　found　that　the　color　temperature　corresponding　to　the　maximal　color　rendering　index　is　different　at　different　phosphors　ratio.　The　experimental　results　indicate　that　color　rendering　index　can　reach　above　90　in　any　color　temperature　region　from　2700　to　13000　K　by　matching　the　ratio　of　red,　green　phosphors　and　silica　gel.　Especially,　color　rendering　index　can　achieve　about　96　in　the　color　temperature　below　4000　K.　Therefore,　the　maximal　color　rendering　index　in　any　color　temperature　can　be　obtained　by　the　choice　and　match　between　blue　LED　dies,　excitating　and　emitting　wavelength,　and　the　scale　between　them.