Activated charcoal masks cannot effectively prevent new coronavirus pneumonia. The main role of activated charcoal masks is adsorption, which can play a role in filtering dust and particles in the air and preventing droplet spraying, but there is no obvious preventive effect for the new coronavirus pneumonia virus. Effective masks to prevent the new coronary pneumonia virus are medical surgical masks, medical N95 masks, or disposable medical masks. In addition, although ordinary masks can also play a role in preventing droplet transmission and can be applied to the general population. However, for infected areas or for health care workers or community workers, ordinary masks are not effective in preventing the new coronavirus and should be needed with the above mentioned medical masks for effective prevention.