In　order　to　determine　the　weight　of　indicators　in　the　former　established　accurate-design　assessment　indicator　system　for　new　generation　steel　plants,　the　indicator　weight　analysis　software　was　developed　by　using　modified　Analytic　Hierarchy　Process　(AHP).　An　expert　team　consisted　of　71　experts　with　different　work　experience　was　employed　to　take　advantage　of　the　developed　software　to　judge　the　indicators＇　weights　for　a　mass-production　slab　steel　plant.　The　obtained　weights　indicate　that　indicator＇s　weight　is　greatly　influenced　by　of　experts＇　experiences.　The　weight　of　an　indicator　depends　largely　on　the　expert＇s　familiarity　to　this　indicator.　The　differences　of　weights　between　the　four　composite　indicators　are　relatively　smaller　when　the　weights　are　obtained　by　the　experts　with　experiences　of　working　in　steel　plants,　having　a　senior　title,　working　over　20　years,　or　working　on　management　position.　The　weights　of　process　operation　high-efficiency　level　and　ecologization　level　rise　with　the　promotion　of　expert＇s　titles　and　increase　of　working　years.　Using　Weighted　Arithmetic　Mean　Method　(WAMM),　the　weight　of　economics/investment　level,　procedure　equipment　level,　process　operation　high-efficiency　level,　and　ecologization　level　are　determined　as　0.285,　0.249,　0.240　and　0.226　respectively.