Silicon nanoporous pillar array (Si-NPA) is prepared by hydrothermally etching method. The copper/silicon nanocomposite thin film (Cu/Si-NPA) is obtained utilizing a reductive deposition method where Si-NPA acts both as a reducing agent and as a substrate. Microstructural analysis indicates that Si-NPA is composed of large quantities of well-separated, quasi-identical silicon pillars which are uniform and perpendicular to the surface. The pillar surface is nanoporous and the pore wall is composed of silicon nanocrystallites with a size about 4 nm. Cu/Si-NPA inherits the morphological characteristic of Si-NPA. The density of the Cu nanoparticles changes alternatively with the geometrical sites of Si-NPA, which leads to the formation of crater-like structures. These results indicate that Si-NPA might be used as an ideal template for synthesizing metal/silicon nanocomposite systems. (C) 2010 Elsevier B.V. All rights reserved.