Objective To investigate the CT imaging findings of different stages of ischemic cerebral infarction. Methods The clinical data of 57 patients with ischemic cerebral infarction clinically confirmed in 1~48h after attack were retrospectively analyzed. All patients were examined by CT and were reexamined every 24h. CT imaging findings were analyzed. Results Among 57 patients in this study, the first CT diagnosis found that 28 cases were abnormal (49.12%). 24h later, reexamination found that 43 cases were abnormal (75.44%), mainly was blockage in blood supply area of cerebral middle artery. There were 4 cases whose onset time was shorter than 6h and CT scan can not clearly show the lesions. Small part of the patients were with slight narrowing of cerebral sulci, The cerebral sulci of 16 patient whose onset time was 6~24h disappeared and the gray matter had no clear boundary. Cerebral sulci had different degrees of shallowing; The onset time of 23 patients were longer than 24h. Large and medium sized arteries in lesions showed high density and there was slight occupying phenomenon. Gyri was asymmetric and part of the midline structures changed. The edges of lentiform nucleus were not clear and the density of brain gray matter decreased and brain white matter were without clear boundaries. Conclusion CT imaging findings in different stages are different. Clinicians should improve the recognition of the positive characteristics of CT imaging.