Social media information is a very important record of human practice in the Internet era, and it is also especial component of social memory. Given the instability of social media platforms, the precious public historical and memorial resources might disappear if the valuable social media information are not preserved well. As a kind of public information organizations, it is necessary for the national comprehensive archives to carry out and take part in social media information archiving actively to play their important function. The national comprehensive archives should act as the dominant power in government social media information archiving, while the collaborator and participant in non-government social media information archiving to provide guidance and assistance for individual and organizations.