The nano-sized Ba(Zr0.2Ti0.8)O3 powder was prepared by citrate sol-gel method. The crystal structure and the particle size of the powder were characterized by XRD. The morphology of calcined powder and the sintered ceramics was observed by TEM and SEM, respectively. The particle size of the powders calcined at 600oC is about 10 nm. The dense ceramics can be obtained at sintering temperature of 1220 oC, which is much lower than that of the powder prepared by the conventional solid method. The effects of Al2O3 additive on the sintering behavior, microstructure and dielectric properties of Ba(Zr0.2Ti0.8)O3 ceramics were also investigated.