Ovarian cancer is the most lethal gynecological malignancy, but the mechanisms of ovarian cancer progression and cisplatin resistance remain unclear. Emerging evidence suggested that ubiquitinconjugating enzyme E2C (UBE2C) was highly expressed in a variety of tumors and acted as an oncogene. In our study, we demonstrated that UBE2C was overexpressed in ovarian cancer by immunohistochemistry (IHC) and The Cancer Genome Atlas (TCGA) database analysis. It was also found that high levels of UBE2C expression predicted worse clinical outcomes in ovarian cancer. After knocking down UBE2C, SKOV3 and A2780 cells showed inhibitory cell proliferation, increased apoptosis by blocking G2/M transition in vitro and in vivo. Besides, the downregulation of UBE2C reversed the cisplatin resistance states of SKOV3/DDP and A2780/DDP cells. Interestingly, CDK1 expression was also downregulated in UBE2C depleted ovarian cancer cells. Furthermore, we found that UBE2C expression was highly correlated with CDK1 expression in ovarian cancer tissues and cell lines, indicating that UBE2C might cooperate with CDK1 in ovarian tumorigenesis. Collectively, our findings strongly supported UBE2C as a candidate oncogene and a potential target for the treatment of ovarian cancer. (C) 2019 Elsevier Inc. All rights reserved.