Objective To explore the changes of serum ischemia modified albumin (IMA) in subarachnoid hemorrhage (SAH) patients with different grades and its prognostic significance. Methods 94 SAH patients were classified into four groups (24 cases of level 1, 27 cases of level 2, 22cases of level 3, and 21cases of level 4) according to Fisher CT classification. The serum IMA levels were detected. Results The IMA levels in Fisher CT level 1, level 2, level 3, level 4 were 36.47±4.05, 42.26±4.67, 45.71±4.92, and 79.63±7.28 respectively. The IMA levels and Chinese clinical neural function defect scale integral (CSS) in SAH patients light group were 37.71±4.14, 6.38±3.13; in medium group were 49.24±5.06, 24.76±7.53; in severe group were 78.33±6.94, 42.67±9.25. The IMA levels and Rankin scale (modified Rankin scale, mRS) of SAH in discharge group with good and modified prognosis were 38.64±4.17, 2.85±3.13, in poor prognosis group were 60.85±6.01, 28.67±8.65. Conclusion The IMA levels are increased significantly in the process of SAH. The IMA level could be used as an indicator to predict the prognosis of SAH.