Abstract: The process of removing iron from aluminum sulfate solution using N-nitroso-phenylhydroxylamine ammonium （CP） as the complexing agent was studied.The effect of CP dosage，acidity of solution，reaction time and reaction temperature on iron removing efficiency were investigated.The optimum reaction conditions were obtained as follows：the CP was dissolved by alcohol-water solution（1∶3 of the volume ratio），CP amount was 1.4 g （as 100 mL of aluminum sulfate solution containing iron），the acidic concentration（concentration of H+ in the solution） was 0.5 mol/L，the reaction temperature was 60 ℃，and the reaction time was 1 h.Under the above mentioned conditions the elimination efficiency was 97.8%，and mass fraction of iron in aluminum sulfate was 0.01%，which was better than the quality standard stipulated in the Industrial Aluminum Sulfate （GradeⅠ，Class Ⅱ，HG/T 2225—2010）.  

Key words: N-nitroso-phenylhydroxylamine ammonium（CP）, aluminum sulfate, complexion, iron removing