Abstract: Benefiting from the rapid development of nano-fabrication technology in the new century, great progress has been made in the research of artificial optical nanostructures. These nanostructures, assembled with plentiful physical mechanisms and capabilities for optical wave manipulation, provide a new means for the effective manipulation of light-matter interaction, and a new approach for the integration, miniaturization and weight reduction of optical devices. Here we summarize the progress in research on artificial optical nanostructures over the last twenty years.