Cross-striped composite structures of Au nanoparticles in anodic porous alumina matrix were fabricated by alternately carrying out anodization and electrodeposition. The length of air gap between Au nanoparticles could be precisely controlled based on the conditions of the cycles of anodization of Al and electrodeposition of Au. The process is simple, has high throughput, and will be useful for the preparation of several types of functional optical devices which require ordered three-dimensional nanostructures. (c) 2006 The Electrochemical Society.