Effect　of　small　amount　of　rare　earth　(RE)　addition　on　electromigration　behavior　of　Cu/SnBi/Cu　solder　reaction　couple　(SRC)　was　investigated　with　current　density　of　5　x　10(3)　A/cm(2)　at　room　temperature　and　100　A　degrees　C,　respectively.　Results　indicate　that　tiny　RE　addition　to　eutectic　SnBi　solder　alloy　can　make　the　energy　of　interfaces　and　grain　boundaries　decrease,　restrain　the　movement　of　dislocations　and　grain　boundary　sliding.　Therefore,　phase　segregation　and　IMC　growth　will　be　effectively　suppressed　which　enhances　the　electromigration　resistance.