Aim: To determine the value of ferrtin in activity in patients with systemic lupus erythematosus. Patients and methods: 67 lupus patients with mean age 34.57 + or - 2.3 who were diagnosed and treated in Rhematology department, Allecgic Immune diseases Center, Bach mai Hospital from December, 2010 to August, 2011. Examination, SLEDAI index and laboratory (ferritin...) have done for all patients. Result: High level of ferritin in lupus patients with high activity 1938 + or - 444.1 ng/ml compared with those medium activity 315.8 + or - 23.5 ng/ml with p 0.01. Real correlation between level of ferritin compared with SLEDAI index in patients with lupus activit, r