Photocatalyst of TiO ₂ hollow particles were used for purify the water at the water surface. To use solar energy at high efficiently and activate the TiO₂, the platinum (Pt) nanoparticles were deposited on TiO₂ surface by pulsed laser deposition (PLD) method (ULVAC,MB94-5006). By irradiation focused Excimer laser lights (248 nm) to the target, plume (which is the aggregate of molecules,atoms,ions,clusters,and so on) occurs and are deposited on the substrate. With PLD, the size of nanoclusters can be controlled by the laser parameters (power denstiy ,the ambient gas pressure,the number of shots, and so on). We found the condition deposited Pt nanoparticles by PLD. There were two kinds of nanoparticles, one’s diameters was about few nm, called small nanoparticles (Fig.1), and other’s was few hundred nm called large nanoparticles (Fig.2). The numerical densities of large nanoparticles was about 1.0×10¹¹ m^-2 and that of small nanoparticle was about 1.0×10¹⁵ m^-2 (Fig 3). We simulate the nanoparticle fabrication mechanism on PLD method and measure the characteristics of Pt nanoparticle deposited TiO₂ hollow particles.