Wheat flour industry plays its roles in local industry development, manpower absorption, and Government’s tax income generation. However, this industry wears out foreign exchange as the raw materials are completely imported. In order to meet domestic demands for wheat flour, in addition to importing wheat, Indonesia also imports wheat flour. The Government’s wheat policy is ruled under Ministry of Finance Regulation No. 213/2011 on Goods Classification System and Import Tariff. This regulation sets wheat flour import tariff of 5%. Such change in policy affects domestic wheat flour supplies and demands. This research aims at: (1) analysing factors affecting wheat flour supply and demands in Indonesia; (2) analysing wheat flour economic policy impacts on the domestic supply and demand; and (3) analysing wheat flour economic policy impacts on wheat flour producers’ prosperity and foreign exchange expenditure in Indonesia. Econometric model in this research constitutes a simultaneous equation system comprising 7 structural equations and 1 identity equation. The wheat flour trade simultaneous model equations are analysed using Two Stage Least Squares (2SLS). The research output indicates two types of policy in that increase wheat flour producer surplus, i.e. policy that sets Indonesia wheat flour import tariff of 5% and policy of 5% increase of wheat flour price. As for the foreign exchange expenditure, policies that cause decrease in this expenditure are Indonesian wheat flour import tariff setting (5%), increase of wheat flour price (10%) and Rupiah depreciation towards US Dollar (10%).