〔Abstract〕 Objective To investigate the value of ultrasonography in children sacrococcygeal teratoma (SCT). Methods The clinical and ultrasonic characteristics of 27 children with SCT who underwent ultrasound examination and were pathologically confirmed in Fujian provincial maternity and children′s hospital from January 2015 to September 2020 were retrospectively analyzed. Results Twenty-six (96%) children were younger than 1 year old, 25 of the 27 SCT patients were mature teratoma and 2 of the 27 SCT patients were immature teratoma. Among 25 mature teratoma, 16 cases (64 %) were cystic, 7 cases (28 %) were mixed and 2 cases (8 %) were solid; Altman classified 19 cases of type I, 3 cases of type Ⅱ, 2 cases of type Ⅲ and 1 case of type Ⅳ; preoperative ultrasonography indicated 20 cases of SCT and 5 cases did not make qualitative diagnosis. 2 cases of immature teratoma were cysto-solid mixed (100 %); All Altman types were type I, and preoperative ultrasound suggested SCT. All 27 children were followed up for 6 months to 76 months, and no abnormalities were observed except 2 cases of mature teratoma with in-situ malignant recurrent yolk sac tumor. Conclusion SCT is most common in children under 1 year old, and ultrasound can make a preliminary diagnosis and classification for most of SCT.