Ba-doping effects on the superconducting properties in the Bi2Sr2-xBaxCaCu2Oy single crystals (0≤x≤0.15) and polycrystalline samples (0≤x≤0.3) have been studied. The results show that Ba２＋ enters the superconducting phase with a solubi-lity limit. For 2212 phase single crystals, the length of c-axis and the supercondu-cting transition temperature Tc both increase with increasing Ba content. For slowly cooled sintered samples, Tc is significantly increased by Ba doping, whereas for quenched samples Tc is little affected. Changes in Tc with Ba doping have been explained by changes in the hole concentration.