Abstract： Objective To detect the mRNA expression and methylation levels of SCNNIB in the epithelial ovarian cancer tissues and normal ovarian tissue,and to analyze the relationship of them in the initiation and progression of epithelial ovarian cancer.Methods A total of 62 epithelial ovarian cancer tissues were obtained in Beijing Youan hospital and Shijiazhuang People's Hospital between September 2019 and December 2022,and contemporaneous 65 normal ovarian tissues pecimens from patients with cervical cancer,uterine leiomyoma or uterine prolapse who underwent total hysterectomy were collected as control group.The methylation levels of SCNN1B gene promoter region were investigated by pyrophosphate sequencing,and the mRNA expression levels of SCNN1B were detected by real-time quantitative PCR(RT-qPCR).Results Compared with the normal ovarian tissues,the methylation levels of SCNN1B promoter were significantly higher in the ovarian cancer tissues(P＜0.05),and the mRNA expression levels of SCNN1B gene were significantly decreased in the ovarian cancer tissues(P＜0.05).Pearson's correlation analysis showed that the promoter methylation levels of SCNN1B were significantly negatively correlated with the mRNA levels of SCNNIB in the ovarian cancer tissues(r=-0.692,P＜0.001).Moreover,the methylation levels and mRNA expression of SCNN1B were significantly related to International Federation of Gynecology and Obstetrics(FIGO)stages and lymph node metastasis in ovarian cancer patients(P＜0.05).Conclusion The decreased expression of SCNN1B due to hypermethylation of its promoter may be involved in the initiation and progression of epithelial ovarian cancer.