Abstract:【Objective】 To analyze the relationship between mean platelet volume (MPV) and clinical prognosis within 30 days of acute cerebral infarction (ACI). 【Methods】 A total of 50 patients with ACI who were diagnosed within 24 hours in our hospital were enrolled in the study. After conventional effective treatment,3 patients died in the hospital,and the remaining 47 patients were discharged after treatment. The mRS score was performed from 47 patients with 30 days after discharge. According to the mRS scores,patients were divided into the good prognosis group (mRS≤2 score,n=33) and the poor prognosis group (mRS>2 score,n=14). The level of MPV were measured at admission,and the relationship between MPV and clinical prognosis of 30 days after ACI was analyzed. The receiver operating characteristic curve (ROC) was used to evaluate the value of MPV as a predictor of clinical prognosis in patients with ACI and the logistic regression analysis was used to determine whether MPV was an independent risk factor for poor prognosis.【Results】 The circulating MPV level of the poor prognosis group was (13.44±1.73) fL immediately after admission,which was significantly higher than (11.17±2.00) fL in the good prognosis group,and the difference was statistically significant (P<0.05). MPV had a moderate diagnostic efficacy for poor prognosis of ACI patients and the area under the ROC curve (AUC) (95%CI) was 0.83 (0.72-0.95). Logistic regression analysis showed that MPV was an independent risk factor for poor prognosis within 30 days of ACI patients. 【Conclusion】 MPV is an independent risk factor for poor prognosis in ACI patients within 30 days,and it is a potential marker for evaluating poor prognosis in ACI patients.