Effects of oxygen partial pressurePO2during low temperature postheat treatments on the superconducting properties of silver‐sheathed Bi2Sr2CaCu2Oytapes were investigated. The critical temperatureTcof the resulting tapes changes systematically withPO2. This variation ofTcis attributed to the change of electronic carrier (hole) concentration by the observation of oxygenK‐edge absorption spectra. The intragranular critical current densityJcis essentially unaffected by the heat treatment, while deterioration in grain connectivity is observed in the specimens treated in reduced‐oxygen atmospheres. The change of anisotropy inJcwith respect to crystallographic orientations is also quite small for the variation ofPO2. ©1996 American Institute of Physics.