This study，based on data captured and analyzed from micro-blog，has got to evaluate the social responsibility of typical media micro-blog account empirically. The study found the reality of media micro-blog’s social responsibility is not optimistic. In addition to more emphasis on social responsibilities of “information production”，media micro-blog has a general lack of sense of responsibility for “cultural heritage”，has been effected by content targeting for its level of social responsibility of “providing entertainment”，presents an obvious polarization on media functions for “educating the public”. Most media micro-blog take a self-protected production ploy，produce less information related to the content of “social supervision”. Media organizations still play a role of superior communicator on the micro-blog platform. The logic that information production of micro-blog is oriented from commercialization to entertainment is eroding the sense of social responsibility of micro-blog.