Close contacts of neocoronavirus pneumonia do not necessarily develop the disease, but if they do they usually develop symptoms within 1 to 14 days, and most will develop the disease within 3 to 7 days. Close contacts of neocoronavirus infection, since neocoronavirus infection has a certain incubation period usually the incubation period is 1~14 days. Therefore, it usually takes 1~14 days from close contact to onset of illness. Moreover, most of the illnesses after exposure to novel coronavirus will be concentrated within 3~7 days. The medical observation period for close contacts of novel coronavirus pneumonia is 14 days, and the current policy in China is to concentrate on isolation for 14 days, especially for close contacts. Nucleic acid testing will be performed during this process, and if the nucleic acid test is negative during the isolation period, the patient can go home. However, after returning home, the patient will be asked to continue home isolation for another 7 days, and the nucleic acid test will be repeated before the end of the period. In addition, close contact does not always lead to infection, especially with strict protective measures and vaccination, which can significantly reduce the chances of infection. Note: The terms “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.