It　is　interesting　and　important　to　develop　cost-effective　and　highly　efficient　method　for　the　selective　reduction　of　nitroarenes　to　produce　the　widely　applied　anilines.　The　catalytic　reaction　directly　driven　by　metal　salts　during　which　the　real　active　species　would　formed　is　a　convenient　way,　but　the　detailed　mechanism　need　further　investigation.　In　this　work,　the　performance　of　different　metal　salts　were　studied,　and　it　showed　that　iron　salts　were　much　more　promising　to　serve　as　catalyst　precursor.　Moreover,　the　reaction　was　remarkably　affected　by　the　type　of　anion.　The　addition　of　other　salts　to　the　iron　salts　mediated　system　had　negative　effect　on　the　reaction.　In-depth　study　suggested　that　the　in-situ　generated　hematite　(alpha-Fe2O3)　nanoparticles　were　the　real　active　species.　Small　and　uniform　alpha-Fe2O3　nanoparticles　could　be　formed　when　the　reaction　was　carried　out　at　relatively　low　temperature,　while　the　generated　nanoparticles　were　much　larger　when　performed　at　higher　temperature.　Under　otherwise　identical　conditions,　the　in-situ　formed　alpha-Fe2O3　also　outperformed　many　other　commercial　benchmark　catalysts.　[GRAPHICS]　.