The　demand　for　rare　earths　in　aluminum　alloy　industry　has　experienced　substantial　growth　in　recent　years.　The　erbium　and　scandium　are　two　effective　rare　earth　additives,　mainly　due　to　its　remarkable　improvement　to　aluminum　alloy　performance.　However,　the　production　process　of　rare　earth　has　caused　significant　environmental　problems.　Hence,　the　analysis　of　environmental　impacts　associated　with　erbium　and　scandium　processing　is　gaining　importance.　In　this　study,　a　life　cycle　analysis　on　the　environment　impacts　of　erbium　oxide　(Er2　O3)　and　scandium　oxide　(Sc2　O3)　was　carried　out　based　on　life　cycle　assessment　(LCA)　method.　The　life　cycle　assessment　results　showed　that　the　production　of　1　kg　of　Er2　O3　and　Sc2　O3　generated　21.7　kg　CO2　eq.　and　743　kg　CO2　eq.,　respectively.　The　leaching　and　purification　process　accounted　for　95%　of　the　overall　water　usage　of　Er2　O3　production.　For　Sc2　O3,　energy　and　chemical　consumption　played　a　key　role　in　reducing　environmental　impacts.　Furthermore,　Er2　O3　appeared　to　have　less　environmental　impact　than　Sc2　O3　on　most　environmental　issues.　A　detailed　review　of　contribution　was　conducted　and　recommendations　for　further　research　were　given.　©　2019　Trans　Tech　Publications,　Switzerland.