Bimetallic CuPtx nanoparticles were prepared in ethanol solution by the wet chemical reduction method using Cu(NO₃)₂ and H₂PtCl6 as starting materials, hydrazine hydrate as a reductant, and polyvinyl pyrrolidone as an organic modifier. The average particle sizes of Cu and Pt nanoparticles were 60 nm and 3 nm, respectively. The small-sized Pt nanoparticles were evenly anchored at the surfaces of large-sized Cu nanoparticles, forming Cu@Pt core-shell structured nanocomposites. In the bimetallic CuPtx nanoparticles, electron was transferred from platinum to copper species, which increased the selectivity of 1-aminoanthraquinone by suppressing the high hydrogenation activity of metallic platinum. The CuPt0.1 bimetallic nanoparticles exhibited higher catalytic activity for the hydrogenation of 1-nitroanthraquinone to 1-aminoanthraquinone than both monometallic Cu and Pt nanoparticles. Over the CuPt0.1 catalyst, the selectivity of 1-aminoanthraquinone was 99.3% at the 1-nitroanthraquinone conversion of 98.9%.