Nucleic acid test refers to the new coronavirus nucleic acid test, abnormal nucleic acid test does not necessarily determine the new coronavirus infection, need to repeat the test, but also need to be combined with the epidemiological history, clinical symptoms, imaging to determine the diagnosis. Usually, a positive nucleic acid test suggests infection with Neocoronavirus. However, due to possible contamination and experimental errors in laboratory tests, abnormal nucleic acid tests may result in false-positive or suspected-positive results, therefore, an abnormal nucleic acid test for the first time does not determine infection with Neocoronavirus. It is recommended to repeat the nucleic acid test and then have the doctor combine it with epidemiologic history, clinical symptoms, and imaging to make a comprehensive judgment. Positive nucleic acid test is usually the primary criterion for diagnosis of neocoronavirus infection, which should also be combined with epidemiologic history such as history of exposure to patients with neocoronavirus pneumonia, history of travel in the community where the case has been reported within 14 days, clinical symptoms such as fever, cough, and malaise, and imaging studies such as ground-glass shadow of the lungs to make a comprehensive diagnosis. Tip: “New coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article were renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.