Spherical nickel powders with the very smooth surface and the uniform size of 300 nm have been manufactured by the chemical reduction and post-treatment technique. The adsorption isotherms of various water-soluble polymers on nickel powders were measured, and their effects on the dispersion stability were investigated. The adsorption amounts of polymers such as PVP ( polyvinyl pyrrolidone), PMAA ( polymethacrylic acid), and PAAm ( polyacrylamide) on nickel powders could be successfully determined by the UV-absorbance analysis technique. Simultaneously, the dispersion stability of nickel powders in the polymer solution was evaluated in terms of the sedimentation behavior and relative coagulation rate. These results showed that the polymers such as PAAm and PVP (Mwt. 1,300,000) were found to be very effective for stabilizing the aqueous nickel dispersion system, and consequently, the coagulation rate of nickel powders in the PAAm solution was almost 100 times slower than that in pure water. (C) 2004 Kluwer Academic Publishers.