The high temperature electrical resistivity and superconducting properties of Bi2Sr2CaCu2Oy heat-treated at 423K in H2 gas were studied. The increment of Tc(on) was recognized on the H-doped samples, but the transition width also increased with the increase of H2 gas pressure. It was recognized that the measurement of Tc for the Bi2Sr2CaCu20y samples under H2 gas pressure above 10.0atm was impossible because of the great increment of electrical resistivity. And it was confirmed that this phenomenon coresponded to the fact that the rapid increase of hydrogen content and unit cell volume were observed at 10.Oatm H2 gas pressure.
