Lu1-xPrxBa2Cu3O7-δ compounds were synthesized in steps of x = 0.1 for 0≤ x≤ 0.9 by solid-state reactions. Bulk superconductivity was observed in samples with x = 0.1, 0.2 and 0.3, even though the two end members of the series are not superconductors. X-ray diffraction studies show that the samples with x = 0.1 and 0.2 are essentially single-phase 1-2-3 materials, whereas the other compounds contain some impurity phase along with 1-2-3 phase. © 1992.