RESUMEN
U.S. Renewable Fuel Standard (RFS) is a mandatory policy for promoting the utilization of biofuels in road transpiration sector in order to reduce the country's dependency on foreign oil and greenhouse gas emissions. U.S. Environmental Protection Agency (EPA) defines the proportion of renewable fuels according to RFS annual target, and requests obligated parties such like fossil fuel refiner, blenders and importer in the U.S. to complete Renewable Volume Obligation (RVO) every year. Obligated parties prove they have achieved their RVO through a renewable fuels certification system, which generates Renewable Identification Numbers (RINs) for every gallon of qualified renewable fuels produced or imported into U.S., RINs is a key for tracking renewable fuel consumption, which in turn is a key for implementing the RFS in the U.S., separated RINs can be freely traded in market and obligated parties could fulfill their RVO through buying RINs from other stakeholders. This briefing paper highlights RFS policy implementing mechanism and marketing tracking, mainly describes importance of RINs, and the method for generating and tracking RINs by both government and fuels industry participants.