The provided digital copyright protective family network system based on domain comprises: a server, and a family network including a HS and different member devices. Wherein, the HS applies corresponding certificate to the family management network and server providing digital content, and forms a domain as the family network; the server takes the domain as integer for management, and communicates only with the user domain instead of device in the domain. The enciphered digital content can transmit and share freely, and the certificate prohibits the digital content out of the domain. This invention protects both the digital content copyright and the free share for legal user, and ensures both-side legal benefits.