Pb- and Bi- containing perovskites exhibit exotic properties owing to the presence of 6s electrons. High-pressure technique is promising method for synthesizing a wide variety of the perovskites. In this paper, the exotic properties of Pb- or Bi- containing perovskites, such as the origin of a large tetragonal distortion in PbVO₃, structural transformation of PbMnO₃ under high pressure, a large volume collapse accompanied with spin state transition in BiCoO₃, polarization rotation in BiCo_1−xFe_xO₃ solid solution, and negative thermal expansion in BiNiO₃ based materials are demonstrated. These properties are attributed to the correlation between 6s orbital of Pb and Bi and 3d orbital of transition metal elements.