The internet has brought about mass of information which in turn has produced multi-faceted impact upon the construction of the public sphere in contemporary society. On the one hand，it has lowered the cost of information acquisition，increased people’s political efficacy，and helped to improve people’s enthusiasm in the involvement of the public sphere. On the other hand，it has brought to the construction of the publics sphere problems that have never existed before，such as unchecked information flood，the public fragmentation，etc.