A　electrostrictive　ceramics　were　designed　by　introducing　Bi(Mg0.5Ti0.5)O-3　into　0.875Bi(0.5)Na(0.5)TiO(3)-0.125BaTiO(3)　with　tetragonal　structure.　All　the　specimens　prepared　by　a　conventional　solid　sintering　technique　exhibit　the　excellent　sintering　ability　with　a　high　relative　density　over　97%.　It　is　found　that,　as　BMT　added,　the　specimens　undergo　a　structure　crossover　from　ferroelectric　P4mm　to　ergodic　P4bm,　and　the　coexistence　of　both　tetragonal　structures　takes　bridge　between　them.　A　large　field-induced　strain　of　0.30%　and　field-independent　strain　coefficient　of　0.0254　m(4)/C-2　occur　at　4　mol.%　BMT　added.　This　material　with　excellent　sinterability　is　suitable　for　the　application　in　actuators　and　microposition　controllers.　(c)　2017　Author(s).