Bioethanol is a liquid biofuel, produced from biological organism that contains appreciable amount of sugar or any material that can be converted into sugar. Indonesia had been producing bioethanol from 2007-2010 from molasses. The research aims to give the projection of bioethanol supply-demand in Indonesia to fulfill the mandatory target of bioethanol utilization in 2025. Using system dynamics modeling, bioethanol production is modeled by identifying the variables and the relations. The modeling and simulation is conducted in STELLA. The research shows that E5 blending will be achieved, but it will not meet E10, therefore it is suggested to expanding the cassava cultivation land at least 12.2% per year, starting from 2019 then 5.7% from 2020. But the scenario cannot cover E20 in 2025. Thus the government should expand 2.8 million Ha of cassava land. Other scenario is choosing other feedstock with higher productivity than 21.8 Ton/Ha/year and conversion efficiency more than 0.1527 kL/Ton.