The effects of heat treatments on the resistivity of BPSCCO-2223 superconductor were studied. The anomalous behavior in high-temperature resistivity was observed. It was shown that upon annealing in N2 at high temperatures, the oxygen escaped not only from Bi-O layer but also from Cu-O layer accompanied with the movement of metal ions. The change in oxygen content and the redistri-bution of oxygen and metal atoms diversified the microstructure of BPSCCO-2223 phase.