Recently, we studied and developed two useful synthesis methods of metal nanoparticles. The first system is wet chemical synthesis of gold nanoparticles using fast reduction. The second one is photodeposition of metal nanoparticles on TiO2. The X-ray absorption fine structure (XAFS) study revealed their unique formation mechanisms different from the conventional mechanisms. Furthermore, we designed and synthesized new multidentate protecting ligand having sulfur functional groups to synthesize small gold nanoparticles efficiently. (C) 2011 Elsevier B. V. All rights reserved.