Ni-P-ultrafine diamond (UFD), Ni-P-carbon nanotubes (CNTs), and Ni-P-UFD-CNTs composite coatings have been electroplated and their hydrogen evolution reaction was studied. Ni-P-CNTs performed the highest catalytic activity though all of the composite electrodes were more active than the Ni-P electrode, which is tightly related to their structures dissolved by hydrogen when prepared. With increasing temperature, the ability of hydrogen evolution of the electrodes was promoted. UFD and CNTs played a cooperating role. The effect of beat treatment was also determined, it is disadvantageous in alkaline environment while not in acid solution. (C) 2004 Elsevier B.V. All rights reserved.