ObjectiveTo explore advances in clinical applications of circulating tumor DNA (ctDNA) for early diagnosis of breast cancer.MethodReviewed on the latest literatures about studies of advances in clinical applications of ctDNA for early diagnosis of breast cancer.ResultsctDNA was a cell-free DNA generated by tumor cells that contained tumor-associated mutations and could dynamically reflect the entire picture of the tumor genome. It was a very important potential tumor biomarker. ctDNA had been widely used in a variety of tumors for early diagnosis, curative effect assessment, and prognosis evaluation due to its advantages such as small trauma and real-time monitoring, and its role in breast cancer had attracted more and more attention.ConclusionEarly diagnosis is critical to improve the breast cancer patients’ overall survival rate and ctDNA plays an important role in early diagnosis and early detection of recurrence and metastasis of breast cancer.