Superconductivity and composition analysis of PbBaSr(Y, Ca)Cu3Oy with fixed ratio of Sr/Ba = 1 were studied. Synthesis condition and superconductivity of Pb(Ba, Sr)2(Y, Ca)Cu3Oy with various ratio of Sr/Ba and Ca/Y were also studied. It was found that Tc increased with increasing Ca concentration, and that Sr-rich specimens allowed to contain more Ca. PbBa0.8Sr1.2Y0.6Ca0.4Cu3O7 showed superconductivity with zero-resistance temperature of 42 K, which was higher than PbBaSrY0.7Ca0.3Cu3O7 with maximum Ca content for Sr/Ba = 1. Decrease in averaged ionic radii of Ba and Sr in Sr-rich compositions would be favorable for the contraction of Cu-O bonds by hole-doping via Ca substitution for Y.
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