liquid biopsy is increasingly widely used in the field of clinical diagnosis and treatment of tumors, and it is an important means to realize "individualized precision medicine" for tumors. In order to scientifically standardize the application of liquid biopsy technology in clinical laboratory, the Laboratory Medicine Branch of Chinese Medical Association and the Clinical Laboratory Center of the National Health Commission jointly formulated the Expert Consensus on the Application of Liquid Biopsy in Clinical Tumor Diagnosis and Treatment and Medical Laboratory Practice, and widely solicited the opinions of clinical oncologists and medical laboratory experts.