In　this　paper,　a　variety　of　blocks　were　grouped　into　the　autoclaved　blocks　and　fired　blocks　as　far　as　the　productive　technology　is　concerned.　In　order　to　compare　the　life　cycle　impacts　of　the　two　kinds　of　the　blocks,　a　life　cycle　assessment　of　two　products　on　the　functional　unit　1m3　was　carried　out　through　the　exploitation　of　mineral　stage,　transportation　stage　and　the　production　of　the　blocks　stage　on　the　considering　of　the　resource　and　energy　consumption　and　the　pollutant　discharges.　The　results　demonstrated　that　the　fired　blocks　appeared　to　have　less　impact　than　autoclaved　concrete　blocks　on　human　health,　marine　ecotoxicity　toxicity　and　terrestrial　ecotoxicity　toxicity　nearly　30%.　The　raw　coal　led　to　the　serious　impacts　on　the　fossil　depletion　through　the　cement　production　stage　of　the　autoclaved　concrete　blocks　accounting　for　45.86%　and　the　gangue　exploitation　stage　of　the　fired　blocks　accounting　for　42.5%.　Assessment　of　the　data　quality　that　the　data　was　of　pretty　high　or　within　the　permission.　The　sensitivity　analysis　and　contribution　analysis　assessment　showed　that　the　conclusion　were　robust.　©　2018　Trans　Tech　Publications,　Switzerland.