A new Cd-containing superconductor with nominal composition of Cd 0.8Ba2(Y0.7Ca0.4)Cu 3.5Oy was synthesized and investigated. The obtained Cd and Ca-doped 123 phase exhibits an orthorhombic (Tc = 80 K) or tetragonal (Tc = 65 K) modification depending on the reaction atmosphere. It was shown that the combined Cd and Ca substitution facilitates the 123 phase formation. The results of the EDX analysis, as well as the comparison of the obtained lattice parameters with those of undoped, Cd-doped, and Ca-doped 123 have shown that both Cd and Ca enter the 123 phase and form a new Cd-Ba-Y-Ca-Cu-O superconducting compound. © 1999 Plenum Publishing Corporation.