Beijing University of Science and Technology researchers and their team (Huang et al.) have surveyed the synthesis of nanoporous perovskite metal oxides and their applications. They discussed various synthesis methods for the preparation-nanoporous perovskite metal oxides and used it for various useful applications. In general Perovskite metal oxides (ABX 3 ), here A-site is an alkaline, earth-alkaline or lanthanide element and B-site preferably with a transition metal. ABX 3 structure tolerates very large distortion with respect to the ideal cubic symmetry and X = O, Cl, Br, F (ex: CaTiO 3 ). Among the f ive compositional flexibilities of ABO 3 , the major response in experimental and predicted (theoretical) reports are done in (A 1+ B 5+ O 3 ), (A 2+ B 4+ O 3 ), and (A 3+ B 3+ O 3 ), In reality, of the 2346 kinds of possible ABO 3 composition only about 265 have been obtained experimentally [ 1 ]. Tolerance factor and stability are playing a vital role in their application ...