Abstract: Objective The aim of this study was to describe the general characteristics of the ovarian tumor in pregnant women at Obstetrics department of Peking University Shenzhen Hospital.Methods A retrospective analysis focusing on clinical characters, diagnosis & treatment and pregnancy outcomes was performed among patients treated at Obstetrics department of Peking University Shenzhen Hospital between 2012-2017.Results A total of 236 cases of ovarian tumors were confirmed by surgery and pathology within 6 years, of which ovarian benign tumors accounted for 52.54% (123/236), followed by tumor-like lesions (42.80%, 101/236) and borderline and malignant tumors (4.66%, 11/236). The most common pathological types were mature cystic teratomas, accounting for 24.15% (57/236), followed by ovarian corpus luteum cysts and ovarian endometriotic cysts, which were 14.41% (34/236). Ovarian tumor pedicle torsion was the most common complication, accounting for 5.51% (13/236), of which 4 were mature cystic teratomas, 1.27% (3/236) of ovarian tumor ruptures, and 1 case of ovarian purulent inflammation with abscess formation, accounting for 0.42% (1/236), 2 cases of hospitalization due to compression symptoms in secondary or the third trimester pregnancy, accounting for 0.85% (2/236), which were both borderline ovarian and malignant tumors. Of the 236 cases, 203 cases were presented as term delivery, 30 premature births, and 2 induced abortions. Of nineteen patients who underwent laparotomy for lower abdominal pain or abdominal distension, 8 patients underwent cesarean section for termination of pregnancy. Six of them had premature delivery and there was no neonatal death. Ten patients underwent adnexectomy or cystectomy and continued pregnancy, and all of them were with a full-term delivery and a maternal-fetal prognosis.Conclusions Ovarian tumors of pregnant women are mainly benign. Ovarian malignant tumors are difficult to find during pregnancy and should be excluded before pregnancy.