Aims: To investigate the predictive value of peripheral blood monocyte count and high density lipoprotein cholesterol (HDL-C) ratio (monocyte/HDL-C, MHR) combined with thromboelastography (TEG) related parameters  in acute Cerebral infarction (ACI). Methods:The study group included 201 patients with ACI, and the comparison group included 201 patients with non-ACI. Using dispersion analysis, changes in MHR and TEG were compared between the two groups. Using logistic regression analysis, valuable measures of model building were screened. Using receiver operating characteristic (ROC) curves, the predictive effect of a combination of single and multiple indices on ACI was evaluated. Based on NIHSS scores, the research team was also divided into a mild nerve injury group (152 cases) and a moderate to severe nerve injury group (49 cases). Compare the changes in the two groups of indicators. Correlations between NIHSS scores and each index were analyzed by pearson correlation. Reasults:Lymphocyte count, monocyte count, MHR, angle, MA, G and A30 were higher in the study group than in the control group. HDL-C, NLR, R and K values were lower in the study group than in the control group, and the differences were statistically significant (P<0.05). Among the indicators, MHR had the highest diagnostic concordance rate and area under the curve (AUC) (0.806 and 0.883, respectively), the highest sensitivity (0.891) for the count of monocyte , and the highest R-value specificity (0.776). Logistic regression analysis showed that MHR>0.367, monocyte count >0.38×10⁹/L, A30>63.1mm and R value<5.0min were independent risk factors for ACI. The 4-factor regression equation has been established: logit(P)=-2.19+1.541* monocyte count -1.731*R+1.466*A30+2.040*MHR. Using this model to predict ACI, the cut-off value was 0.409, the sensitivity was 84.1%, the specificity was 86.1%, the AUC was 0.912, and the diagnostic concordance rate was 85.1%. Specificity, diagnostic concordance, and AUC were higher than single index assays. The moderate-to-severe neurological deficit group had higher counts of neutrophil count, monocyte count, MHR, NLR, Angle, MA, G, and A30 than the mild neurological deficit group. Lymphocyte counts and HDL-C were lower in moderate-to-severe nerve injury groups than in mild nerve injury groups, and the difference was statistically significant (P<0.05). The NIHSS score was positively correlated with the counts of neutrophil count, monocyte count, MHR and NLR (P<0.001). Among them, the NIHSS score had the strongest correlation with MHR (r=0.674, P<0.001). Conclusions:MHR>0.367, monocyte count >0.38×10⁹/L, A30>63.1mm, R value<5.0min were independent risk factors for ACI. Combining the four factors for detection is more effective in predicting ACI. The elevated MHR can be used as an index for judging the severity of ACI.