Abstract:We have been getting a deeper and deeper understanding of tumor, and have made great progress in cancer diagnosis and treatment. With the advancement of technology, precise diagnosis and treatment of cancer will become a trend in the future. At present, tissue biopsy is widely used but there are still some problems such as sampling bias and that it is an invasive procedure. Thus, developing an efficient approach to detecting tumors has become the focus of relevant researches. It is found that circulating tumor DNA (ctDNA) is derived from tumors, reflects the genetic information of tumors well, and changes dynamically with the progression of tumor. In recent years, the distinctive role of ctDNA has attracted much attention and has been extensively studied. This article will review the research progress and application prospect of ctDNA.