Ovarian teratoma with blood flow signal is not necessarily malignant. Ovarian teratoma is divided into mature teratoma and immature teratoma, generally mature teratoma is benign, immature teratoma is malignant, no matter mature teratoma or immature teratoma may have blood flow signal, can not rely on the blood flow signal to determine the benign or malignant. In addition to ultrasound, other tests, such as serologic examination, X-ray, CT, etc., are also needed to determine the benign or malignant nature of teratoma. Among them, serologic examination includes alpha-fetoprotein, serum human chorionic gonadotropin, carcinoembryonic antigen, CA125, etc. If these examinations suggest malignancy, it is necessary to perform pathological examination after surgical resection to confirm the final diagnosis. If you have ovarian teratoma, you should consult a doctor in time, improve the examination, make a clear diagnosis and timely treatment.