The　molecular　structure　models　of　asphalt　binder,　ethanol　additive,　and　ethanol-based　foamed　asphalt　were　constructed　through　the　Molecular　Dynamics　(MD)　method.　The　standard　ethanol-based　foamed　asphalt　model　was　employed　to　describe　the　modifier　with　its　different　compositions,　including　10%,　20%,　and　30%　ethanol.　The　simulation　calculations　were　done　for　the　ethanol-based　foamed　asphalt　molecular　models　under　the　NPT　and　NVT　ensembles.　The　density,　glass　transition　temperature,　and　radial　distribution　function　of　ethanol-based　foamed　asphalt　molecular　models　were　obtained　to　verify　the　rationalization　of　asphalt　models　and　analyze　the　variation　of　density　parameters　with　temperature　and　ethanol　content　for　ethanol-based　foamed　asphalt　molecular　models.　The　results　show　that　the　simulated　densities　of　the　asphalt　binder　and　three　ethanol-based　foamed　asphalt　molecular　models　remained　constant　with　the　increase　of　simulation　steps.　The　simulated　density　values　of　basic　and　10%-ethanol-based　foamed　asphalt　molecular　models　are　close　to　0.9　g　cm(-3).　The　simulated　densities　of　20%-ethanol-based　and　30%-ethanol-based　foamed　asphalt　molecular　models　were　0.8　g　cm(-3)　and　0.75　g　cm(-3).　Meanwhile,　the　simulated　density　values　of　both　asphalt　binder　and　all　ethanol-based　foamed　asphalt　decreased　with　the　increase　in　temperature　and　ethanol　additive　dosage.　The　glass　transition　temperatures　of　basic　asphalt　binder,　10%-ethanol-based,　20%-ethanol-based,　and　30%-ethanol-based　foamed　asphalt　occurred　in　the　range　of　275-295　K,　330-350　K,　330-350　K,　and　320-340　K,　respectively.　In　contrast,　the　glass　transition　temperature　of　ethanol-based　foamed　asphalt　increased　with　the　increase　of　ethanol　additive　dosage,　indicating　that　adding　ethanol　additive　significantly　improved　the　high-temperature　resistance　of　matrix　asphalt.　In　the　radial　distribution　function　diagrams　of　all　samples,　the　first　strong　peak　appeared　at　0.85-1.3　&　Aring;,　and　the　second　strong　peak　appeared　at　1.95-2.35　&　Aring;.　Moreover,　both　peaks　increased　with　the　increase　of　ethanol　additive　dosage,　suggesting　that　the　contact　between　ethanol　molecules　and　asphalt　molecules　was　closer　with　the　rise　of　ethanol　additive　dosage.