Objective To study MRI application value in the diagnosis of acute brainstem infarction. Methods 42 patients with acute brainstem infarction from December 2013 to December 2015 in our hospital were included into the study, and the clinical data and MRI imaging data was collected to comprehensive analyze the MRI imaging features and pathological characteristics of the acute phase brainstem infarction. Results 42 cases of acute phase single patients by pathological examination of 23 patients with brainstem infarction, 19 patients with multiple, found infarcts 61, among them including the lesion site of infarction cerebral medulla oblongata, bridge, the midbrain. Infarction range between 1 mm-28 mm in diameter, including scope of infarction in 1 mm-10 mm of 19, 10 mm to 20 mm there are 31, 20 mm-28 mm has six. Infarct morphology of dot (24), the article sheet (18) or funicular (14). MRI shows the result is: 25 cases for such signal in T1WI, 14 cases of T1WI is slightly low signal; 4 cases for such signal in T2WI, 35 cases for high signal in T2WI; DWI is high signal can. Conclusion MRI in the clinical diagnosis of patients with brainstem infarction, can present the three-dimensional structure of the brain stem, comprehensive clearly shows that the number of infarction, position, size and shape, and the localization diagnosis and qualitative diagnosis of brainstem infarction has high diagnostic coincidence rate, which could be the first choice in the clinic and is worth of further promotion and application.