Abstract: Taking a low grade iron tailings of fine and refractory ibmenite from the reduction roast and low intensity magnetic separation from Guizhou as raw materials，high quality of Nano-TiO₂ powder was prepared by the process of acidified roasting-hydrolysis. The structure of Nano-TiO₂ powder was characterized by XRD，SEM，TEM and BET etc.，and its catalytic degrading performance on the 4-nitrophenol was evaluated with the refractory phenolic compounds 4-nitrophenol as object. The results indicated that the TiO_{2 2}owder being prepared belongs to the nanometer anatase concentrate with the particle size of tens of nanometers; TiO₂ powder appears in meso-structure with an average pore diameter of about 5 nm; TiO₂ powder shows very good photocatalytic degradation on 4-nitrophenol，and the degradation rate is more than 60% within 240 min.