The novel porous ZnO nanoflakes were fabricated by a facile two-step method containing preparation of precursor ZnCO3 and subsequently calcination of ZnCO3. The as-prepared products were analyzed by X-ray diffraction, scanning electron microscopy, and thermalgravimetric analysis. The results reveal that the porous ZnO nanoflakes were in the diameter and thickness of several to tens micrometers and 100500 nm, respectively. The microwave absorption properties of porous ZnO nanoflakes were investigated by the network analyzer, which exhibit the minimal reflection loss of -34.5 dB at 10.7 GHz with only thickness of 1.5 mm. The effective absorption (below -10 dB) bandwidth can be tuned between 7.0 GHz and 17.1 GHz by tuning absorber thickness of 1.0-2.2 mm. Thus, the porous lamellar ZnO could be used as a promising absorbing material with the features of high efficiency absorption, wide-band and light weight. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.