The　ball　grid　array　(BGA)　component　was　selected　as　the　specimen　with　the　outmost　edge　row　cross-sectioned　to　investigate　subgrain　rotation　behavior　influenced　by　grain　boundaries　under　thermal　shock　cycles　condition.　To　study　the　subgrain　rotation,　the　crystal　orientation　was　obtained　by　electron　backscattered　diffraction(EBSD).　The　results　showed　that　a　lot　of　subgrains　were　generated　in　the　solder　joints　due　to　cyclic　stress　caused　by　the　high　mismatched　coefficient　of　thermal　expansion　(CTE)　under　the　thermal　shock　cycles　condition.　And　the　subgrains　near　the　chip-side　and　the　twin　grain　boundaries　were　analyzed　in　detail　to　estimate　the　impact　of　the　grain　boundaries　on　the　subgrain　rotation　behavior.　The　results　showed　that　a　large　number　of　subgrain　boundaries　and　several　newly　generated　subgrains　appeared　at　the　tilted　twin　grain　boundaries　and　the　chip-side　in　the　solder　joint　after　200　thermal　shock　cycles.　Meantime,　the　subgrain　rotation　axes　and　misorientation　angles　were　both　calculated,　and　the　dislocation　slip　was　recognized　to　closely　relate　to　subgrain　rotation　by　comprehensively　analyzing　the　rotation　axes　and　misorientation　angles.　The　subgrain　rotation　axes　of　the　chip-side　was　about　Sn　[101]　and　[001],　while　the　subgrains　rotation　near　the　tilted　grain　boundaries　in　the　same　dominant　grain　was　different　from　that　of　the　subgrains　near　the　chip-side,　and　subgrain　rotation　axes　were　[101],　[100]　and　[110].　There　were　also　a　large　difference　in　the　direction　of　subgrain　rotation　between　the　chip-side　and　the　tilted　twin　grain　boundaries.　The　subgrain　rotation　axes　at　both　sides　of　twin　grain　boundaries　were　similar,　but　the　rotation　directions　were　opposite.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.