Based　on　the　practice　of　magnesium　production　in　China,　a　quantitative　evaluation　of　the　environment　impact　was　carried　out　according　to　the　theory　and　framework　of　life　cycle　assessment(LCA)　study.　The　major　gaseous　pollutants　including　CO2,　SO2,　NOx,　CH4,　HF　and　particulates　were　calculated.　The　accumulative　environmental　performances　of　different　energy　use　strategies　and　the　characterization　results,　including　abiotic　depletion　potential(ADP),　global　warming　potential(GWP),　acidification　potential(AP)　and　human-toxicity　potential(HTP)　were　compared.　The　results　show　that　the　direct　emission　of　fuel　combustion　in　the　process　is　the　major　contributor　to　the　pollutants　emission　of　magnesium　production.　Global　warming　potential　and　acidification　potential　make　the　main　contribution　to　the　accumulative　environmental　impact.　The　different　fuel　use　strategies　in　the　practice　of　magnesium　production　cause　much　different　impacts　on　the　environmental　performance.　The　accumulative　environmental　impact　of　coal　burned　directly　is　the　highest,　and　that　of　producer-gas　comes　to　the　next,　while　that　of　coke-oven　gas　is　the　lowest.