0.92(Na0.5Bi0.5)TiO3-0.08BaTiO3　ferroelectric　ceramics　modified　with　different　amounts　of　La2O　3　and　MnCO3　were　prepared　by　the　conventional　mixed　oxide　method.　The　effects　of　La　and　Mn　doping　on　microstructure　and　dielectric　behavior　of　the　ceramics　were　studied.　The　relaxor　behavior　of　doped　specimens　became　more　evident.　It　mainly　attributed　to　the　change　of　the　order　degrees　induced　by　doping:　the　order　degree　of　A-site　is　decreased　by　the　intervention　of　La　and　the　relaxor　behavior　is　enhanced　accordingly.　However,　the　Mn　doping　will　erect　new　disorder　system　at　B-site,　which　is　an　important　contribution　to　the　relaxor　behavior.　Na0.5　Bi0.5)0.92Ba　0.08TiO3;.