Abstract: According to the characteristics that the disseminated extent of iron mineral was fine,the content of manganese was high,the magnetizing roast followed by magnetic separation process was adopted to utilizing the iron for a kind of manganese-containing fine grained limonite ore in Hunan province.Based on XRD analyses and microstructure analysis,the mineral composition and dissemination relationship of roasting product were discussed.By the optimum conditions that the roasting temperature 850℃,the roasting time 60min,the quantity of coal addition 4%,the particle size of grinding -44μm 85%~90%,the magnetic field intensity 159kA/m,and by three-stage cleaning,the iron concentrate,with the grade of iron was 55.72%,the grade of Mn was 7.03% and the recovery of Fe was 80.84%,was gained.In the roasting product the main minerals were magnetite and manganese oxides.Most of the magnetite was fine grained,exited in the aggregates forms with manganese mineral and gangue.The magnetite was very difficult to be liberated because of the special existing form.