Magnesium　is　a　promising　lightweight　and　green　metallic　engineering　material,　but　the　environmental　impact　of　primary　magnesium　production　stage,　especially　greenhouse　gas　(GHG)　emissions　cannot　be　ignored.　In　this　study,　the　life　cycle　energy　consumption　and　GHG　emissions　caused　by　the　production　of　primary　magnesium　in　the　years　of　2003-2013　in　China　were　calculated;　the　factor　decomposition　was　conducted　to　analyze　the　GHG　emissions　of　magnesium　production　process　by　using　logarithmic　mean　Divisia　index　method(LMDI),　including　energy　GHG　emission　factors,　energy　structure,　energy　consumption　per　ton　of　primary　magnesium,　production,　emissions　per　unit　of　dolomite　and　ferrosilicon,　and　dolomite　and　ferrosilicon　consumptions　per　ton　of　primary　magnesium.　The　results　showed　that　GHG　emissions　of　primary　magnesium　production　increased　260.29*104　t　CO2eq　in　total　from　2003　to　2013.　The　variety　magnesium　production　contributed　the　biggest　part　of　GHG　emissions,　accounting　for　418.17%.　The　energy　structure　took　second　place　on　the　contribution　of　GHG　emissions,　accounting　for　-161.49%.　The　nest　part　was　energy　consumption　per　ton　of　primary　magnesium,　accounting　for　-138.97%.　While,　the　contribution　of　energy　GHG　emission　factors,　emissions　per　unit　of　dolomite　and　ferrosilicon,　and　dolomite　and　ferrosilicon　consumptions　per　ton　of　primary　magnesium　was　relatively　small,　which　were　0.88%,　0.00%　-2.72%　-4.73%　and　-11.13%,　respectively.　Thus,　it　is　the　key　methods　to　reduce　GHG　emissions　by　optimizing　the　energy　structure　and　decreasing　the　energy　consumption.　©　2016　Trans　Tech　Publications,　Switzerland.