We　reported　the　reliability　of　Sn0.3Ag0.7Cu　(SAC0307)　solder　joints　under　electrical　and　thermal　coupling　fields,　where　the　c-axes　of　Sn　grains　were　all　nearly　parallel　to　the　direction　of　current　and　thermal　flows.　In　these　studies,　individual　electromigration　(EM),　individual　thermomigration　(TM),　and　thermoelectric　coupling　migration　behaviors　were　investigated　by　applying　a　current　density　of　10(4)　A/cm(2),　and　a　temperature　gradient　of　10(3)degrees　C/cm　at　Cu/SAC0307/Cu　solder　joints,　respectively.　The　SEM　and　EBSD　were　utilized　to　characterize　the　morphologies　and　crystal　orientations　of　each　solder　joint.　The　results　indicated　that　the　Cu　atoms　tended　to　migrate　to　the　anode　side　under　EM.　The　thickness　of　an　interfacial　intermetallic　(IMC)　layer　at　the　anode　increased　3.93　mu　m.　In　addition,　the　Cu　atoms　diffused　toward　the　lower　temperature　side　under　TM,　and　the　thickness　of　the　IMC　layer　at　cold　side　increased　1.72　mu　m.　When　the　solder　joints　were　experiencing　the　coupling　fields　with　the　same　directions　of　current　and　thermal　flows,　the　thickness　of　IMC　layer　at　anode　side　(cold　side)　could　increase　up　to　7.67　mu　m.　The　results　showed　that　the　effect　of　thermal　flow　could　assist　to　accumulate　the　IMC　at　the　anode　side,　and　accelerate　the　migration　of　Cu　atoms.　This　research　could　help　to　further　understand　the　reliability　behaviors　of　SAC0307　solders　under　the　service　environment.