Porous ZnO micro-flakes with hexagonal morphologies were obtained during an integrated autoclave tests and pyrolysis process, in which the hexagonal precursor was first synthesis using commercial ZnO powders and chloroform (CHCl3) by autoclave tests, hexagonal ZnO micro-flakes were finally obtained through a simple pyrolysis method. The products were characterized via FE-SEM, TEM, XRD, TGA and PL spectrum. The results show that the porous ZnO hexagonal micro-flakes composed of ZnO single crystalline nanoparticles have thickness of about 100 nm, width of about 2 mu m. The possible growth process is suggested by providing a series of intermediate morphologies during the shape evolution of porous ZnO micro-platelets on basic of the SEM observation. (C) 2007 Elsevier B.V. All rights reserved.