Objective　To explore the relationship between C-type lectin-like receptor 2 (CLEC-2) on platelet surface and the severity of acute cerebral infarction and cerebral artery stenosis.Methods　Prospectively selected 211 patients with acute cerebral infarction who were hospitalized for the first time as the infarction group,the patients were grouped according to the NIHSS score and cranial MRA examination results on admission,and 105 healthy patients were collected as the control group.Venous blood of all patients was collected for CLEC-2 detection on the day of admission,and the level of CLEC-2 between each group was analyzed.Results　The level of plasma CLEC-2 in the infarction group was significantly higher than that in the control group (P＜0.001).The level of CLEC-2 in the mild,moderate and severe acute cerebral infarction subgroups gradually increased,and the difference between the two groups was statistically significant (P＜0.001).After adjusting for confounding factors,the concentration of CLEC-2 (OR=1.034,95%CI 1.020~1.048,P<0.001) was an independent risk factor for cerebral artery stenosis in patients with acute cerebral infarction.Receiver operating characteristic (ROC) curve analysis showed that the area under the curve for CLEC-2 to predict cerebral artery stenosis was 0.862 (95%CI 0.812~0.912,P<0.001);the best cut-off value was 266.40pg/ml,predicted the sensitivity of cerebral artery stenosis was 80.3%,and the specificity was 80.9%.Conclusion　Elevated levels of CLEC-2 can assess the severity of ACI patients,is an independent risk factor for cerebral artery stenosis,and has certain value in predicting cerebral artery stenosis.