Objective To explore the ultrasonic features of Ovarian dysgerminoma. Methods The features of clinic and ultrasonography of 4 patients with ovarian dysgerminoma confirmed by pathology were reviewed. Result Four patients with Ovarian dysgerminoma were young women. Ovarian dysgerminomas are characteristically single solid hypoechoic masses with well-encapsulated, circumscribed, posterior echo attenuation, regular inside echoes, lobulation, with abundant blood flow signals on CDFI in adnexec area. Conclusion Ultrasonogram of ovarian dysgerminoma were characteristic. It is helpful in clinical diagnosing.