【S】objective:To discuss the value of ROC curve evaluation of color doppler ultrasound blood flow imaging (CDFI) systolic and diastolic velocity ratio (S/D) in differentiating benign and malignant ovarian tumors,in order to provide a basis for clinical diagnosis.Methods: 96 patients with ovarian cancer were selected as cancer group from December 2015 to December 2018 in our Hospital,96 patients with ovarian benign lesions were selected as control group at the same period,the thrombolysis in myocardial infarction,S/D value were assessed by CDFI examination and determination in all patients,the S/D value in differentiating benign and malignant ovarian tumors was evaluated by ROC curve.Results:The thrombolysis in myocardial infarction,S/D value of cancer group were significantly higher than those of control group,the difference was statistically significant (P < 0.05).In terms of the sensitivity, specific, accuracy degree for differentiating benign and malignant ovarian tumors,when thrombolysis in myocardial infarction for ≥Ⅱlevel as the critical value,they were 81.25%,83.33%,82.29%,when S/D value by ROC curve for ≥2.20 as the critical value,they were 87.50%,81.25%,84.38%,when they joint,they were 95.83%,93.75%,94.79%,when they joint were significantly higher than those of when thrombolysis in myocardial infarction for and PSV separate identification, the difference was statistically significant (P < 0.05),but when they separate identification were basically the same , there was no statistically significant difference (P > 0.05).Conclusions:Thrombolysis in myocardial infarction and S/D value by ROC curve has good effectiveness in differentiating benign and malignant ovarian tumors,and when they joint can further improve the identification efficiency.