A series of samples with nominal compositions of La3CaxBa4-xCu7Oy,(0 <= x <= 4.00) was prepared by the solid state reaction method. Single phase materials were obtained for 0 <= x <= 1.25 samples which had an oxygen stoichiometry, 16.021 <= y <= 16.587, equivalent to 6.866 <= z <= 7.109 per unit cell with a formula of La1.29Ca0.43xBa1.71-0.43xCu3Oz. An evidence of the hole doping was observed by substituting Ca ions for Ba ions. It was interesting that increasing the Ca substitution accompanied an increase in the oxygen stoichiometry to a maximum value of 7.109 with a hole concentration of 0.311 for x = 1.00 sample. A correlation between the Tc and the hole concentration was plotted and the result was very similar to that found in the YBa2Cu3O7-x superconductor.
