Aim: To analyze the difference in results of diffusion-weighted imaging DWI) for patients with aphasia and non-aphasia following striatocapsular infarction (SCI), and investigate the localization of the infarction in patients with different aphasia types. Methods: 1 152 patients with acute middle cerebral artery infarction in 24 hours hospitalized in Department of Neurology, Beijing Tiantan Hospital from June 2003 to October 2005 were selected. Their disease was accorded with the criteria of cerebral infarction on the 4th national cerebral vascular disease conference; all patients informed and agreed to the detection were given magnetic resonance imaging (MRI), DWI, and magnetic resonance angiography (MRA) within 48 hours after onset. Totally 78 patients were recruited into this study, 38 of them showed SCI on the PWI, and 21 of the 38 patients' SCI located on the left hemisphere with right handedness were selected as objects including 12 males and 9 females with average age of (56±11) years. 2 Aphasia was assessed by the West Aphasia Battery (WAB) in 4 days after onset. Simens trio3.0T was used to perform the T1, T2, DWI, PWI and MRA. 3 χ2- test (Fisher's exact test) was used to compare the difference between the counted results. Results: The 78 patients with acute middle cerebral artery infarction were recruited, 38 of them showed SCI on the PWI, and 21 of the 38 patients' SCI located on the left hemisphere with right handedness were involved in the result analysis. 1 DWI results: 9 SCI patients (42%) of the 21 ones presented additional ischemic lesions involving the same side cortical areas; while 3 non-aphasia cases (21%) of 12 ones had additional cortical lesions, there were significant differences between them (P=0.001), all the rest 9 non-aphasia patients had SCI on the left hemisphere in DWI. 2 Conventional MRI results: No corresponding acute cortical lesions was found in any aphasic patients. 3 Relation between cortical lesions and aphasia revealed by DWI: 3 patients with global aphasia appeared posterior-temporal lesion, 2 ones appeared anterior-frontal and inferior parietal lesion. Among the 4 cases with motor aphasia, 3 ones appeared insular or frontal lesion, 2 ones appeared parietal or temporal lesion. Both of the 2 sensory aphasia patients appeared inferior parietal or posterior-temporal lesion. Conclusion: 1 Aphasia due to SCI in the acute stage may be attributed to direct cortical injury, which can be demonstrated by DWI, even though it might be invisible in conventional imaging. 2 DWI shows cortical lesion might be relevant to the type of aphasia.