Dense PTC ceramics were prepared with BaTiO3 nanopowders synthesized by hydrothermal method. BaCO3 and Ti(OC4H9)4 were used as barium and titanium sources, and Y(NO)3·6H2O as the donor dopant respectively. The average grain size of the powders obtained after hydrothermal treatment at 160°C for 9h was about 30nm with cubic structure. Mn(NO3)2 was introduced to the as-prepared nanopowders in order to improve the PTC effect. After sintered at 1280°C, the PTC ceramic samples exhibited sufficient resistance jump ratio(1.086×103) around Curie temperature, the density of which was 5.81g/cm3(96.5% of the theoretical density).