Abstract： Objective To discuss the significance of EEG in the auxiliary diagnosis and prognosis of a-cute cerebral infarction. Methods To analyze 106 cases of acute cerebral infarction in patients with EEG, CT and clinical data. Results Early acute cerebral infarction (<24 h) EEG abnormality rate of 63.6%, CT ab-normal rate of 25% ,difference was very significant (P<0.01). As the disease development,24 h after the CT-positive rate was 88. 4%, significantly higher than the rate of EEG abnormalities. Conclusion EEG reflects the state of brain function, very sensitive to the ischemie cortex, in the evaluation of acute cerebral infarction has cer-tain advantages, especially in the ultra-early period diagnosis of acute cerebral infarction area. EEG have predic-tive value in disease evolution and prognosis of cerebral infarction. CT are reflected in the state of the organiza-tional structure. Combination of both, provide an objective basis for cerebral infarction in diagnosis, treatment, prognosis.