Epigenetic changes are closely related to carcinogenesis, tumor progression and prognosis, which have a considerable potential in assisting the precision and minimally invasive management of cancers. The progress of detection techniques for DNA methylation, hydroxymethylation and histone modification has promoted the research works of liquid biopsy targeting epigenetic markers, and recently, important progress has been made in tumor location, early diagnosis, clinical staging, evaluation of treatment response, monitoring of recurrence and prognostic prediction of solid tumors.