The　electromigration　test　was　conducted　in　Cu/Sn-58Bi/Cu　solder　joint　with　high　current　density　of　10(4)　A/　cm(2).　Results　showed　that　a　large　number　of　whiskers　with　natural　weed　appearance　were　observed　at　the　cathode　side　in　such　a　short　current　stressing　time.　Furthermore,　some　secondary　whiskers　were　attached　to　the　primary　whiskers,　which　has　never　been　reported　before.　We　presumed　the　vapor-solid　(VS)　mechanism　to　explain　the　oxide　whiskers　growth,　which　was　quite　different　from　the　traditional　theory　that　the　compressive　stress　took　on　the　driving　force.　In　conclusion,　due　to　the　over-Joule　heating　effect,　the　metal　oxide　whiskers　were　synthesized　in　bulk　quantities　by　thermal　evaporation　of　Sn　oxide　and　Bi　oxide.