Abstract: With the advent of “we-media” era， emergent Internet public opinions play a more and more important role in peoples life. Taking the micro-blog discussions on the massive explosion in Tanggu port， Tianjin as one example， the participants of emergent Internet public opinions are divided into the government， the network media， the people involved and the general public. By using the grounded theory， it was found that the three influencing factors of emergent internet public opinion evolution are the release of official information， the participants motivation and their behavior decision. Then， in combination with the evolution process of emergent internet public opinions， the promoting or inhibiting effect the participants may exert in the dissemination process of emergent internet public opinions was analyzed to put forward a series of measures (including improving the governments guidance mechanism) in order to reasonably guide and control the development of emergent internet public opinions.

Key words: emergent internet public opinion, evolution of internet public opinion, grounded theory