Bi2WTi3O12 ceramics are fabricated by conventional solid-state reaction process. XRD analysis reveals that Bi2WO6 is the main phase and Bi4Ti3O12 is the second phase. With increasing temperature the sample first appears metallic behavior, then strong electrical fluctuations above 100°C, and finally exhibits stable nonlinear properties characterized by semiconductivity above 300°C at low field (E ≤ 100V/mm). The Arrhenius law for electrical conductivity by thermal activation is not suitable to explain the anomalous results. Based on the phase transition of tungsten trioxide from room temperature to about 300°C, the electrical properties of Bi2WTi3O12 ceramics can be explained.