Abstract: Ovarian cancer is one of the common gynecologic neoplasms，which is ranked the most lethal among gynecological cancers in women. Since lacking of obvious clinical symptoms and effective early diagnostic methods for screening，more than 70% of patients are diagnosed at the advanced stage always accompanied with ascites and abdominal widespread metastasis. The prognosis in those patients is poor. Therefore，it is particularly important to improve the survival rate of ovarian cancer by early detection and early diagnosis. In recent years，rapid progresses in epigenetics make a great significance for early diagnosis，new treatment and better prognosis of ovarian cancer. DNA methylation，the most common form of epigenetic modification，can lead to many changes，such as chromatin structure，DNA conformation，DNA stability and interaction between DNA and protein. The epigenetic modification could change gene expression，which plays an important role in the formation and progression of ovarian cancer.

Key words: Epigenesis, genetic, DNA methylation, Ovarian neoplasms, Genes, CpG islands