Objective:To classify breast cysts through contrast-enhanced ultrasound and provide scientific basis for the treatment of breast cysts.Methods:Forty-five patients diagnosed with breast cysts by routine ultrasound were treated with pe-ripheral intravenous injection of ultrasound contrast agent.Among them,intracapsular injection of ultrasound contrast agent was performed to observe the perfusion of contrast agent in septal cysts.Cyst sclerotherapy was performed for simple cysts and simple septal cysts,surgical treatment was performed for thick walled cysts,and follow-up observation was performed for duc-tal ectasia.Results:Among the 45 patients,20 cases were simple cysts and 25 cases were complex cysts.Among the com-plex cysts,19 cases were septal cysts(including 3 cases of ductal ectasia,16 cases of simple septal cysts)and 6 cases of thick-walled cysts(4 cases of intraductal papilloma,1 case of intraductal papillary carcinoma and 1 case of invasive ductal carcinoma).Thirty-six cases of cysts underwent sclerotherapy,6 cases underwent surgical resection and 3 cases of ductal ec-tasia were followed up.Conclusion:Contrast-enhanced ultrasound can accurately evaluate the classification of cysts and has important clinical value in guiding the treatment of breast cysts.