In this study, a vibration mill using cog-disk mediums, which replaces the ball medium with a cog-disk medium in conventional vibration mill, was developed to achieve high-impact pulverizing in order to attain effective pretreatment of lignocellulosic biomass for producing the bio-ethanol as renewable energy. Pulverization of Japanese cedar and enzymatic hydrolysis of pulverization powder were carried out to evaluate the vibration mill using cog-disk mediums. As the results, the vibration mill using cog-disk mediums pulverized submillimeter particles of Japanese cedar powder into micron particles. Also the crystallinity of pulverization powder was simultaneously decreased during pulverization. Then saccaharification efficiency of holocellulose was reached over 70% in enzymatic hydrolysis of pulverization powder at pulverizing time of 60 min. This pulverization shortened the amount pulverizing time fifth to make high saccharification capability powder comparing with the conventional vibration ball mill. Therefore this vibration mill using cog-disk medium had better pulverization efficiency for pretreatment of lignocellulosic biomass.