Previously, we have reported a novel bioethanol production system based on solid-state fermentation (SSF) and forage rice, which is used in a silage-making process. In this study, we evaluated the productivity of valuable materials via SSF using various plant materials other than forage rice. Italian ryegrass, sorghum, cassava, and other plant materials are also promising for SSF. Laboratory-scale SSF experiments using raw materials of Italian ryegrass yielded a maximum of 99 mg/g of dry matter of ethanol and other valuable materials (organic acids and soluble sugars). The conversion rates were almost the same as that of the forage rice. The nutritional value of the fermented products as livestock feed either improved or was similar to that of silage.