Hermaphroditism is due to abnormal development of the gonads. In patients with true hermaphroditism, both ovarian and testicular gonads are present. It is reported that there are three cases: (1) one side is ovary and the other side is testis, accounting for about 40%; (2) one side is ovary or testis and the other side is ovotestis, also accounting for about 40%; (3) both sides are ovotestis and there is fibrous tissue between the two, accounting for about 20%. The clinical manifestations of true hermaphroditism: external genitalia can be male, female or mixed type, but male type is more common, accounting for about 2/3. Most of them have a uterus, but it is often underdeveloped or deformed. More than half of them have menstruation or periodic hematuria. Examination of the gonads reveals two sets of gonads, male and female, but they are not fully developed. The causes of true hermaphroditism may be: 1) monozygous sex chromosome mosaicism, which is the result of meiotic or mitotic errors; 2) non-monozygous sex chromosome mosaicism which is often the result of fusion of two fertilized eggs or two fertilizations of a mandarin; 3) translocation of the Y chromosome to the X chromosome; 4) autosomal mutation genes. In familial patients, the mode of inheritance is autosomal recessive or dominant. Treatment of true hermaphroditism: The principle is that the testicular tissue should be removed to prevent malignant transformation. The ovaries and testes should be carefully distinguished during surgery, and the testes should be removed to preserve the ovaries; if it is difficult to distinguish, all the gonads should be removed for safety. If it is difficult to distinguish the testes, all the gonads can be removed for safety. Generally, the procedure is corrected in women.