PbBr-based layered perovskite film was successfully prepared by successive deposition of amphiphilic ammonium bromide monolayer which was formed on a subphase of saturated aqueous PbBr2 solution. In this work, we studied the formation process of layered perovskite structure on the subphase while evaluating reflection spectra of amphiphilic ammonium monolayers and observing topographs of the monolayer using a scanning probe micrograph. The reflection spectra demonstrated that the layered perovskite structure was formed on the subphase of saturated aqueous PbBr2 solution. From the reflection spectra and the AFM image, the reasonable formation process of the layered perovskite structure on the subphase was proposed. (c) 2005 Elsevier B.V. All rights reserved,