Abstract： Objective:To identify the factors associated with long-term survival and guide the decision for primary surgery in patients with advanced high-grade serous ovarian cancer(HGSOC).Methods:In this case-control study, clinical parameters, including surgical and non-surgical associated factors, were collected and compared between the patients with short-term (<2 years) and long-term (>5 years) survival who all underwent primary debulking surgery (PDS) followed by carboplatin and paclitaxel chemotherapy from January 2004 to December 2016. Univariate analysis was examined by chi-square test and multivariate analysis was performed by logistic regression analysis.Results:There were 95 cases long-term survival (LTS group) and 77 cases short-term survival (STS group) in 698 newly diagnosed HGSOC patients with International Federation of Gynecology and Obstetrics (FIGO) stage Ⅲc and Ⅳ who met include and exclude criteria. (1) Univariate analysis showed that the proportion of complete cytoreduction with no visible residual disease (R0) at PDS and platinum sensitivity in LTS group were significantly higher than those in STS group ( P<0.01). The surgical complexity score (SCS), the preoperative serum CA 125 level and the ascites volume in the LTS group were significantly lower than those of the STS group (all P<0.05). In the LTS group, the preoperative incidence of lesions in retrograde peritoneum of the bladder, serosal and mesangial membrane of the small intestine, upper abdominal peritoneum and liver parenchyma were significantly lower than those in the STS group (all P<0.05). Multivariate logistic regression analysis showed that platinum sensitivity ( OR=0.016, 95% CI: 0.004-0.063, P<0.01), ascites volume >500 ml ( OR=3.193, 95% CI: 1.285-7.930, P=0.012), and SCS ≥8 ( OR=17.433, 95% CI: 2.281-133.25, P=0.003) were independent factors affecting long-term survival ( P>0.05). (2) Totally 37 of 95 in long-term survival and 16 of 77 in short-term survival achieved R0 cytoreduction at PDS. Univariate analysis showed that preoperative serum CA 125 level, preoperative lesion score, preoperative lesion (DS) score, ascites volume, platinum sensitivity,and SCS were significantly correlated with the R0 PDS (all P<0.05). Multivariate analysis showed that ascites volume >500 ml ( OR=5.199, 95% CI: 2.015-13.409, P=0.001), DS >2 ( OR=15.264, 95% CI: 5.843-39.874, P<0.01) and SCS ≥4 ( OR=4.176, 95% CI: 1.618-10.777, P=0.003) were independent factors associated with R0 cytoreduction. In patients with DS ≤2 or SCS <4, but not those with DS >2 or SCS ≥4, R0 cytoreduction was significantly associated with long-term survival. Conclusion:The intrinsic biology of tumor is the factor influencing long-term survival of advanced HGSOC patients, and those who present with wide intraperitoneal metastases and need to remove multiple organs may not benefit from R0 cytoreduction.