Objective: To analyze the ultrasound image features of ductal carcinoma in situ (DCIS), and their relations with the pathological profiles. Methods: The clinical data of 66 DCIS patients were reviewed, and then the ultrasound image features of the patients and the relationships between the lesion size and calcification, infiltration and Her-2 expression were analyzed. Results: Of the 66 patients, the lumps in 42 cases were larger than 1 cm, which presented as hypoechoic areas with irregular shape and unclear border in the ultrasound image; the lumps in 24 cases were less than or equal to 1 cm, which presented as duct dilation (7 cases), small nodule (9 cases), or gland thickening (8 cases). In DCIS larger than 1 cm, the calcification rate on ultrnsound examination was lower but infiltration and Her-2 positive expression rate were higher than those in DCIS less than or equal to 1 cm (all P<0.05). The coincidence rate of ultrasound examination for diagnosis of DCIS with the final pathological results was 51%. Conclusion: DCIS has its own characteristics in ultrasound images, and the lump less than or equal to 1 cm is often accompanied with calcification, while the lump larger than 1 cm may predict a poor prognosis.