Objective To investigate the relationship between the neurological deficit and carotid atherosclerotic plaque in patients with acute cerebral infarction(CI). Methods From August 2015 to December 2019, 1 022 patients with CI were selected from Ruijin Hospital. According to National Institute of Health stroke scale(NIHSS) score, the patients were divided into mild group(n=572) and moderate to severe group(n=450). Meanwhile, according to carotid color Doppler ultrasound, all patients were divided into non-carotid plaque group(n=365) and carotid plaque group(n=657). Furthermore, the carotid plaque group was divided into single plaque group(n=249), double plaque group(n=91) and multiple plaque group (n=317) based on the number of plaques, and according to the echo characteristics and the plaque stability, the plaque group was divided into stable plaque group (n=316) and unstable plaque group (n=341). The difference of the incidence of carotid plaque between the mild and moderate to severe group was analyzed. Results There were 71.8%(262/365) mild patients in the non-plaque group and 43.1%(283/657) mild patients in the plaque group. There was significant difference between the two groups（χ²=57.604, P<0.01）. There was significant difference in the proportion of moderate to severe patients among single plaque, double plaque and multiple plaque groups（χ²=57.604, P<0.01). The proportion of unstable plaque in the moderate to severe group（57.4%） was higher than that in the mild group(45.8%). Multivariate Logistic regression analysis showed that the possibility of NIHSS>3 in the plaque group was 3.691 times higher than that in non-plaque group. Conclusions The severity of neurological deficit in patients with acute cerebral infarction may be related to the incidence of carotid atherosclerotic plaques, the number and character of plaques.