This paper investigated the effectiveness and power of Weibo (Microblog) through the sequentially periodical studies of the each phases of the public crisis caused by "7·23" EMU trains read-end accident, including brewing, breaking out, spreading and appeasing. It is also analyzed the key external factors from public opinions in the failure of emergency management by the Ministry of Railways on this issue. Moreover, the paper explored the regulatory factors in behind, especially from the perspective of the drawbacks resulted from the government-enterprise unification at the Ministry of Railways and failing governmental regulations. Besides, it is believed that the lack of updated responsibilities, values and awareness in the Ministry of Railways also led such consequences to the accident. This paper made comparative studies with similar incidents in Germany and Japan as well, discussing their revelations to crisis management in China. <<