The effects of MnO2 content on the structure and dielectric properties of the SBN-glass-ceramics were studied. The results show that a small amount of MnO2 doping of the SBN-glass-ceramics can make their microstructure become denser and more uniform and MnO2 doping of the SBN-glass-ceramics, as a grain growth inhibitor, has an evident effect on the reduction of grain sizes. The Mn ions exist in the form of Mn3+ and Mn4+ ions in the SBN-glass-ceramics, as confirmed by XPS measurements and Mn3+ and Mn4+ ions easily form charge defect complexes, which causes the leakage current densities of the SBN-glass-ceramics to obviously decrease. And a small amount of MnO2 doping of the SBN-glass-ceramics can effectively decrease the dielectric loss of the materials. When 0.05 mol% MnO2 is added to the SBN-glass-ceramics, the BDS is up to 1470.6 kV/cm and the theoretical energy storage density reaches the maximum value of 9.2 J/cm(3). (C) 2017 Published by Elsevier Ltd.