Copper (Cu) plate-like and shrub-like micro-scale crystallites were synthesized by a facile hydrothermal method using formaldehyde (HCHO) as the reducing agent in NaOH aqueous solution at 180 degrees C. The X-ray diffraction patterns indicate that the as-synthesized Cu crystallites were well crystallized and with pure phase. FESEM and TEM images reveal that the final plate-like products consist of lager numbers of triangular and hexagonal plates with the edge length ranging from 0.5 to 4 mu m and with the thickness ranging from 250 to 350 nm, and the shrub-like products are composed of some dendrites. SAED and HRTEM images prove that the Cu plates are singe crystals and covered by {111} facets. The effect of capping agent, NaOH concentration, reaction time and temperature on the morphologies of the final products has been investigated, and their possible formation mechanisms were also discussed. (c) 2006 Elsevier B.V. All rights reserved.