Targeted genetic testing for tumor patients can be performed with a variety of specimen samples, including cellular specimens after puncture biopsy for genetic testing, surgically removed tissue specimens for testing, and blood specimens, malignant pleural effusion, peritoneal effusion, pericardial effusion, and even cerebrospinal fluid for testing. The two methods commonly used in clinical practice are tissue cell biopsy and liquid biopsy. Both methods have advantages and disadvantages. Tissue cell biopsy requires obtaining tumor tissues from patients, and the results are reliable and are the standard detection method, but the operation of taking specimens is invasive, and some specimens are more difficult to take. Liquid biopsy is a method taken when tumor tissue specimens cannot be obtained. The advantage is that it is non-invasive and can be tested multiple times, and the disadvantage is that there is a possibility of false negatives. In conclusion, clinicians should adopt the appropriate testing method according to the actual condition of the patient.