Abstract: Internet has already been applied to every corner of the society，including social moral monitoring. This article makes a detailed analysis of the differences between the traditional and online social moral monitoring，discussing from the following four respects the limitations of traditional social moral monitoring the Internet breaks: space limitation，time limitation，power concentrating limitation and system limitation. The limitations of the Internet are also pointed out，which are false informafion，limited coverage and the possibility of Internet violence.

Key words: social morality, Internet monitoring, the Internet, net user, Internet violence