Objective To explore clinical values of ischemia modified albumin(IMA) in early diagnosis of ischemic stroke(IS). Methods 86 cases of IS patients were divided into 5 groups according to the time of IS onset 3h, 6h, 12h, 24h and 48h group. The serum IMA levels in IS patients and 20 health controls were tested by using albumin cobalt binding test. Results The concentration of IMA in 20 healthy controls was 75±8.6U/ml. IS onset 3h later, IMA increased significantly to 99.1±11.7 U/mL. Whiles 48h later, the serum IMA concentration was reduced to 87.3±26.5 U/mL. The IMA concentration of IS patients in group of 3 h, 12 h and 24 h were significant higher than that of healthy controls, the P values were 0.004, 0.049 and 0.002 respectively. Conclusion The ischemia modified albumin is useful biochemical marker for early diagnosis of ischemic stroke.