Objective To investigate the clinical imaging features and diagnostic value of lacunar infarction in CT and MRI. Methods The clinical data and imaging data of 74 cases of lacunar infarction admitted to our hospital from September 2017 to December 2018 were retrospectively analyzed. The detection rates of lacunar infarction by MSCT and MRI were compared.To summarize the imaging features of lacunar infarction in different examinations. Results The total detection rate of lesion of lacunar infarction by MRI was 97.29%. The total detection rate of of lesion of lacunar infarction by MSCT was 83.78%.The total detection rate of MRI was significantly higher than that of MSCT. The difference was statistically significant (χ2 =7.889, P<0.05).For patients whose onset time was <6h, CT scan can not clearly show the lesion, only a small number of patients showed slight narrowing of cerebral sulcus. For patients whose onset time was 6-24h, the cerebral sulcus disappeared and had varying degrees of shallowness. There was no clear boundary between gray matter and no obvious mass effect. For patients whose onset time was >24h, there was sign of high density in middle cerebral artery and obvious occupying phenomenon, the gyrus was asymmetrical, the structure of midline changed, the edge of the lenticular nucleus was blurred, the density of the gray matter relatively decreased, and the interface of the white matter was blurred. The T1WI sequence of lacunar infarction showed a low-signal lesion with clear boundary, and the T2WI sequence showed highsignal lesion. In the FLAIR sequence, the acute phase showed a high-signal lesion, and the chronic phase showed reducing of signal in the center of sac and high signal around the sac.In the DWI sequence, the acute phase or the subacute phase showed high-signal lesion, and in the enhanced mode, the acute and late phase or subacute phase may showed significant enhancement. Conclusion Both CT and MRI can effectively display the image features of lacunar infarction in different periods. MRI has better detection rate of lacunar infarction than CT, which is beneficial to clearly identify tiny lesions.