One simple high-temperature solution phase method has been developed to synthesize large-scale, monodisperse, hexgon β-Cu2S nanoplates. The hexgon nanoplates have edge lengths of 9 ± 0.5 nm and thicknesses of 4.5 ± 0.2 nm and self-assemble closely into three-dimensional superlattices. The present results suggest that the simple method might be useful for the synthesis of monodispese hexagon nanoplates for many other chalcogenide semiconductors with hexagonal symmetry structure.