There is no specific measurement of the survival time of the new coronavirus on paper, but foreign studies have found that it can survive for 24 hours on cardboard, 3 hours on aerosols, 4 hours on copper, and 2-3 days on plastic and stainless steel surfaces. The survival time on cardboard is 24 hours, but it does not mean that these 24 hours are infectious, because the virus has its own decay outside the body, human infection depends on the number of viruses, virulence, and finally decide whether the person is infected. Within 24 hours, it is possible that the early hours of the infectiousness is very strong, and at a later stage, although the virus is detected, but the infectiousness has been greatly reduced or has no infectiousness.