There are several important applications for photochromic materials in some areas, such as civil, military, space areas and so on. To solve the instability issue which exists ubiquitously in photochomic materials, Prof. Guocong GUO’s group, State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, CAS, have introduced the hybrid ideas of inorganic components and organic components to obtain novel inorganic-organic hybrid photochomic materials bearing individual merits, and discussed the photochomic mechanism by theory computations, characterizations and crystallography, thus coming into being own unique photochomic research system. A 3D inorganic open-framework compound built from exclusively octahedral units and exhibiting a wavelength-dependent photochromic response was firstly found during the syntheses of perovskite hybrids materials. Moreover, an unprecedented 3D metal-organic framework compound displaying photochromic property was obtained during the preparation of metal-organic complexes. The results from crystallography, spectroscopy and theory computations show that the photochromism in the two compounds above-mentioned comes from photoinduced radicals, which result from inorganic halogenate salt and oxygen atoms of carboxylic acid, respectively. Those results above have been issued in Angew. Chem. Int. Ed. (Wang et al., 2008, 47, 3565-3567 and Zhang et al., 2008, 47, 4149-4152), and have been highly praised by international peers.