In this study, process of nano-sized metal particles were investigated for newly liquid-solid (metal oxide-alcohol) system. Many noble metal oxides have merits in metal particles fabrications, for example, these materials are decomposed by only heating in air. That is, noble metal oxide don't use strong reduction atmosphere. This reduction is ecologically clean, because many noble metal oxides are not toxic and during decomposition 02 is evolved. We have reduced noble metal oxides by ultrasound and tried to fabricate silver nano metal nanoparticles at room temperature, and investigated property of silver oxide in decomposition. By choosing suitable conditions, it is reasonable to expect that these simple sonochemical process can be extended to obtain nano-sized metal particles.