Here we report the preparation of two different types of macroporous silver particles (round and coral) by simple chemical reduction using ammonium formate. We also discuss the chemical mechanism of silver particle and macroporous silver particle formation. The synthesized round type and coral-type porous silver particles were 20-50 mu m and 30-150 mu m in size and their pores were 100-200 nm and 1-2 mu m across, respectively. They were characterized by particle distribution analysis, X-ray diffraction, and scanning electron microscopy. (C) 2009 Elsevier B. V. All rights reserved.