Objective To explore the application value of CT texture analysis for evaluating Ki-67 expression in patient with esophageal squamous cell carcinoma.Methods Sixty-one cases of pathologically confirmed esophageal squamous cell carcinoma patients were selected to obtain the Ki-67 protein expression status of the patients'pathological tissues,and the patients were divided into a high-expression group and a low-expression group.All patients underwent plain and enhanced chest CT within two weeks before surgery.Lesions delineation and texture feature extraction of esophageal cancer were obtained via Omni-Kinetics software.The texture parameters included Min Intensity,Max Intensity,Median Intensity,Mean Intensity,Deviation,Skewness,Kurtosis,Entropy,Energy,Correlation,Haralick,short run high grey level emphasis(SRHGLE),short run low grey level emphasis(SRLGLE),long run high grey level emphasis(LRHGLE),long run low grey level emphasis(LRLGLE),Grey Level Nonuniformity,Run Length Nonuniformity.The differences of texture features among different Ki-67 expression groups were compared,and the receiver operating characteristic(ROC)curve was used to analyze the predictive value of Ki-67 expression in patient with esophageal cancer.Results In plain CT images,the SRHGLE and Grey Level Nonuniformity of the high expression group were significantly higher than those of the low expression group(P=0.010,0.002,respectively).In enhanced CT images,the Mean Intensity,Entropy and Grey Level Nonuniformity of the high expression group were significantly higher than those of the low expression group(P=0.026,0.037,0.001,respectively),and SRHGLE and LRHGLE of the high expression group were significantly lower than those of the low expression group(P=0.016,0.010,respectively).The area under the curve(AUC)of texture features in plain CT were 0.676-0.740,and the AUC of combined diagnosis reached 0.770[95%confidence interval(CI):0.645,0.868],and sensitivity and specificity was 0.921,0.565,respectively.In enhanced CT,the AUC of texture features were 0.629-0.750,the AUC of combined diagnosis increased to 0.903(95%CI:0.799,0.964),and sensitivity and specificity was 0.816,0.826,respectively.Conclusion CT texture analysis can early and non-invasively predict Ki-67 expression in patient with esophageal squamous cell carcinoma,it can be used as an imaging marker to evaluate the proliferative activity of esophageal cancer cells,and may provide diagnosis and treatment information for clinical decision-making of esophageal squamous cell carcinoma.