We report the study of the [Y0.8Ca0.2]SrBaCu 2.80(BO3)0.2O6.4 compound which is a superconductor with critical temperature of 45 K. This compound was prepared by the solid state reaction method under normal conditions of pressure and temperature, replacing 0.2 of oxianion borate (BO3)3- in the copper site of [Y0.8Ca0.2]SrBaCu3O 7-δ. TC was determined by measuring the magnetic susceptibility using a SQUID detection system. The X-ray difractogram revealed a monophasic pattern, Rietveld analysis suggested an orthorhombic crystalline structure belonging to the Pmmm spatial group with a = 3.826 Å, b = 3.861 Å and c = 11.561 Å. © 2004 Elsevier B.V. All rights reserved.