A series of (Na1/2Bi1/2)Cu3Ti4O12 (NBCTO) ceramics were prepared by solid-state reaction at different sintering temperatures. The crystal structure，microstructures，dielectric properties and complex impedance and the corresponding temperature dependences were investigated. It has been revealed that the NBCTO ceramics has quite similar electrical properties with those previously found in CaCu3Ti4O12ceramics. The NBCTO ceramics prepared at sintering temperatures between 990℃ and 1060℃ exhibit low-frequency ε′ larger than 10000 at room temperature. With the increasing of sintering temperature，both ε′ and the grain size in microstructure first increase and then decrease. Although large difference is observed in their dielectric properties and complex impedance for the various NBCTO ceramics，there exist some common features. Whereas only one dielectric relaxation is seen at room temperature or lower temperatures，two are seen in the dielectric spectra within the measured frequency range of 40 Hz—10 MHz at higher temperatures.