The life cycle of ethanol derived from miscanthus has been evaluated to determine its environment and economic viability. Net energy consumption, production cost and emission are estimated considering three scenarios (S1: all classes of land; S2: prime land; S3: marginal land, are used for miscanthus cultivation). Depending on the scenarios net energy consumption, production cost and emissions are found to be varied from 12.1 to 12.5 GJ m^-3, 776.7 to 811.3$ m^-3 and 0.7 to 1.3 t-CO₂e m^-3, respectively. Although energy consumption and production cost is slightly varied among the scenarios, the variation seems to be robust in the case of GHG emissions, where carbon dynamics play an important role. This study revealed that miscanthus is a promising feedstock for ethanol even if it is grown on marginal land which may abate competition with food crops and improve the farm economy in Ontario, Canada.