Piezoelectric　ceramics　Sr1.95Ca0.05NaNb5O15+y　wt%MnO2(SCNNM)　with　y　ranging　from　0　to　1.5　were　prepared　by　solid-state　reaction　method.　The　results　indicated　that　the　calcined　SCNNM　ceramics　retain　a　single　phase　of　tetragonal　tungsten-bronze　structure　with　y&le0.7.　When　y≥1.0,　a　secondary　phase　was　observed.　The　addition　of　a　little　MnO2　could　decrease　the　sintering　temperature,　promote　grain　growth.　The　dielectric,　piezoelectric　and　ferroelectric　properties　of　the　SCNNM　ceramics　significantly　increased.　At　room　temperature,　the　SCNNM　ceramic　with　y=0.5　exhibits　the　optimum　properties:　piezoelectric　coefficient　d33=190　pC/N,　mechanical　quality　factor　Qm=1455,　planer　and　thickness　electromechanical　coupling　factors　Kp=13.4%　and　Kt=36.5%,　dielectric　constant　Εr=2123,　loss　tangent　tanδ=0.038,　remanent　polarization　Pr=4.76　μC/cm2,　coercive　field　Ec=12.68　kV/cm,　and　curie　temperature　Tc=260　oC.