卵巢癌是死亡率最高的妇科恶性肿瘤之一，初期常无症状，多数患者往往在晚期或出现转移后才发现，随着研究的深入，发现其发生、发展、诊治与DNA异常甲基化有着密切的关系。通过研究DNA甲基化机制，有助于卵巢癌的早期诊断、治疗和预后判断。游离DNA是细胞外游离存在于体液中的DNA，可在肿瘤细胞坏死、凋亡等过程中产生，在卵巢癌的诊治中有着重要的研究意义。本文就DNA异常甲基化在卵巢癌的研究进展及甲基化研究方法做综述。

Ovarian cancer is one of the most common malignant tumors in gynecology. In early stage, patients usually don’t have any symptoms. So when it was diagnosised, the cancer often had transferred to other tissues. And it always made bad influence to the treatment. Therefore, it is important to find new biomarkers which contribute to the diagnosis of ovarian cancer in the early stage. Based on other researches, the aberrant DNA methylation has been associated to the ovarian cancer, including the diagnosis in early stage, treatment and prognosis. The methylation of cell-free DNA which come from the tumor cells maybe a kind of important biomarkers of ovarian cancer. This review is telling about the newest researches and the use in ovarian cancer.