Roles of interleukin-31 (IL-31) in the development and progression of human epithelial ovarian cancer are largely unknown. Studies report that the polymorphisms, rs7977932 C>G and rs4758680 C>A in IL-31, affect the expression level of IL-31. In the present study, we examined 412 patients with epithelial ovarian cancer and 428 healthy individuals to explore whether these polymorphisms are associated with the epithelial ovarian cancer in Chinese women. The genotype of the polymorphisms in each individual was identified. The associations of the polymorphisms with patients' clinical characteristics and outcomes were evaluated. For rs7977932, the frequency of the CG/GG was significantly decreased in patients with epithelial ovarian cancer. However, the frequency of the rs4758680 CA/AA was significantly increased in those patients. Moreover, the frequency of rs7977932 CG/GG genotype was significantly higher in patients with less advanced FIGO stages. Kaplan-Meier curve showed that patients with CG/GG genotypes of rs7977932 had a decreased risk for recurrence compared to those with CC genotype. Our findings suggested that rs7977932 and rs4758680 of IL-31 may be associated with the development and progression of the epithelial ovarian cancer in the Chinese population. IL-31, therefore, may be a potential therapeutic target for the development of drugs to treat the disease.