The　piezoelectric　ceramics　of　(K0.5Na0.5)NbO3+xMnCO(3)　(KNN+xMn)　were　prepared　by　the　conventional　solid-state　method,　and　the　effect　of　Mn　doping　on　the　sintering　characteristics,　microstructure　and　electrical　properties　of　the　ceramics　was　investigated.　The　results　show　that　proper　Mn　doping　promotes　sintering　performance,　induces　lattice　to　change　from　orthorhombic　to　tetragonal　and　improves　electrical　properties　of　KNN　ceramics.　When　the　content　of　Mn　is　2　mol%,　the　relative　density　of　KNN　ceramics　is　93.2%,　the　phase　structure　is　more　close　to　tetragonal　and　the　best　electric　properties　are　obtained,　such　as　epsilon(r)　is　526,　tan　delta　is　2.3%,　d(33)　is　207　pC/N,　k(p)　is　45%　and　Q(m)　is　181.