Objective To explore the relationship between serum tenascin C(TN-C),irisin(Irisin) and the severity and prognosis of patients with acute ischemic stroke(AIS).Methods 203 AIS patients admitted to our hospital(January 2017 to December 2019) were selected as the AIS group.According to the National Institutes of Health Stroke Scale(NIHSS) and Modified Rankin Scale(mRS),they were divided into severe group(n=52),moderate group(n=87),mild group(n=64) good prognosis group(n=125) and poor prognosis group(n=78),another 74 healthy people at the same period were selected as the control group,and the serum TN-C and Irisin level were compared between the groups,Pearson correlation analysis was used to analyze the correlation between serum TN-C and Irisin levels and NIHSS,mRS scores,ROC curve analysis was used to analyze the prognostic value of serum TN-C and Irisin levels in AIS.Results The serum TN-C levels in the AIS group were significantly higher than those in the control group,and the Irisin levels were significantly lower than those in the control group(P<0.05);the serum TN-C levels in the severe group were significantly higher than those in the moderate group,and the Irisin levels were significantly lower than those in the moderate group(P<0.05);the serum TN-C levels in the moderate group were significantly higher than those in the mild group,and the Irisin levels were significantly lower than those in the mild group(P<0.05);the serum TN-C levels in the poor prognosis group were significantly higher than those in the good prognosis group,Irisin levels were significantly lower than those in the good prognosis group(P<0.05);pearson correlation analysis showed that the serum TN-C level in the AIS group was positively correlated with NIHSS and mRS scores (P<0.05);the serum Irisin level was negatively correlated with NIHSS and mRS scores(P<0.05);ROC curve showed that the AUC,sensitivity and specificity of TN-C+Irisin predicting the prognosis of AIS were higher than those predicted by TN-C and Irisin alone.Conclusion Elevated serum TN-C level and decreased irisin level can reflect the severity of AIS and adverse prognosis,the combined determination of the two can improve the predictive value of the prognosis of AIS patients,and can be used as an indicator to evaluate the prognosis.