Objective:To observe the ultrasound characteristics of galactostasis at various physiological stages,so as to improve the diagnosis of galactostasis.Methods: The ultrasound data of 56 patients with galactostasis were retrospectively analyzed and the ultrasound characteristics were summarized.The ultrasonic manifestations of different physiological stages were compared.Results: During the lactation period,there were extensive mammary duct ectasias and floating weak signals were found in the mammary duct during pure galactostasis; large non-responsive fluid areas exhibited formations of honeycomb-like multilocular fibrous septa; and these cavities ruptured with abscess when secondary infection occurred.During the later lactation period,the dilated galactophores became hypoechoic or anechoic,which,together with the dot-like echoes of residual breast milk or macular strong echoes, formed mixed signals of retention cysts.After menopause,the galactophores atrophy occurred; the accumulation of galactostasis desiccated into patches or powder,which caused thick hyperechoic dots or multiple hyperechoic streaks in the galactophores or parenchyma.Conclusion: Ultrasonic images of galactostasis vary with the physiological and pathological changes of the mammary glands,and are related to the duration of galactostasis,absorption,concentration and desiccation of lactation.