ABSTRACT Objective: To evaluate the value of ultrasonography in diagnosis of Ovarian Tumors in immature females and to study the sonographic characteristics of them.Methods Thirty-one cases of ovarian tumors in immature females between Jan.2013 to Dec.2016 were collected in this retrospective study.All patients were examined by color doppler ultrasound before operation.The sonographic features，clinical manifestations and pathological results of them were analyzed. Results Among 31 cases of pediatric ovarian tumors，21 cases were benign tumors and tumor like lesions，9 cases were malignant tumors.The pathology result showed that 61.29%（19/31）of the cases were germ cell tumor.11 cases with cystic sonographic features were proved benign tumors by pathology. Solid tumors were most commonly associated with malignant （80%，4/5）, especially the lamp with color doppler flow signal(100%, 3/3). When the ultrasound showed mixed or multilocular mixed echo combined color doppler flow signal inside, the possibility of malignancy was 100% (3/3) .Conclusion： The malignant or benign pediatric ovarian tumors can be judged in most cases according to their sonographic characteristics，which offer important help in the clinical management.