The　recently　discovered　large　flexoelectricity　in　relaxor　ferroelectrics　has　rekindled　considerable　research　interest.　In　this　paper,　several　Sm-doped　Pb(Mg2/3Nb1/3)O3-xPbTiO3　(PMN-xPT)　ferroelectric　ceramics　were　prepared　and　the　relationship　between　flexoelectricity　and　PT　content　was　systematically　investigated.　The　largest　flexoelectric　response　(∼550　μC/m)　was　observed　in　the　Sm-doped　PMN-32PT　ceramic,　which　should　be　accounted　for　in　the　reorientation　of　the　polar　nanoregions.　At　room　temperature,　the　flexoelectric　response　of　Sm-doped　PMN-32PT　ceramic　is　an　order　of　magnitude　higher　than　that　of　the　parent　PMN-PT　ceramics　and　even　50%　higher　than　that　of　Bi-PMN-32PT　ceramic　(∼300　μC/m).　Such　a　big　increment　is　directly　related　to　the　greater　local　structural　heterogeneity　caused　by　Sm3+　ions　into　PMN-PT.　Therefore,　the　result　presented　in　this　paper　verifies　that　introducing　local　structural　heterogeneity　is　a　feasible　approach　to　achieve　ultrahigh　flexoelectricity.　©　2021　Author(s).