A systematic investigation on structure, dissociation behavior, chemical bonding, and magnetic property of Cr-doped Cu-n clusters (n = 9-16) is carried out using the mean of density functional theory calculations. It is found that CrCu12 is a crucial size, preferring an icosahedral Cu-12 cage with the central Cr dopant. Smaller cluster sizes appear as on the way to. form the CrCu12 icosahedron while larger ones are produced by attaching additional Cu atoms to the Cretin, core. The presence of Cr dopant obviously enhances the stability of CrCu clusters in comparison to that of pure counterparts. Exceptionally stable CrCu12 has an 18-electron closed shell electronic structure, mimicking a noble gas in the viewpoint of superatom concept. Analysis on cluster electronic structure shows that the interplay between 3d orbitals of Cr and 4s orbitals of Cu has a vital role on the magnetic properties of CrCu clusters.