Objective To investigate the difference of ovarian benign diseases and healthy regulatory T cells(Tregs) and tumor markers CA125 and CA19-9 in patients with ovarian cancer, and to analyze their correlation with clinicopathological factors and prognosis. Methods We selected 43 cases pathologically diagnosed ovarian cancer patients in gynecological department from October 2016 to October 2017 in our hospital as a malignant group, another 55 cases of benign ovarian patients treated in the same period as benign group, 50 cases of healthy physical examination women as control group. The Tregs number and expression levels of tumor markers CA125 and CA19-9 in ovarian cancer were compared among the three groups, and their relationship with clinicopathological factors and prognosis was analyzed. Results The proportions of Tregs in the malignant and benign groups were higher than those in the control group, and the proportions of Tregs, CA125 and CA19-9 in the malignant group were higher than that in the benign group (P<0.05). There are no significant difference in the proportion of Tregs, CA125 and CA19-9 levels and the age of patients. The level of CA125 was related to the lymph node metastasis, tumor stage, and histological type in patients with ovarian cancer. Tregs ratio was associated with lymph node metastasis and tumor staging in patients with ovarian cancer. The CA19-9 level was only related to tumor stage (P<0.05). After 12 months of follow-up, the median survival time of Tregs low group was higher than that of Tregs high group (P<0.05).There was a significant positive correlation between the number of Tregs and CA125 in ovarian cancer (P<0.05), but not with CA19-9 (P>0.05). Conclusion Tregs, CA125, and CA19-9 can all be promising markers for clinical diagnosis, treatment and prognosis of ovarian cancer.