2channel is the most popular online-community site in Japan, where millions of people are discussing or chitchatting about various topics. The communication in 2channel shows dynamic social phenomena such as positive/negative communication, polarization of opinions, slander called flaming, etc. In this paper, we assume the existence of underlying prevailing structures that motivate peoples participation. The structural equation model of 2channel, which is obtained on the basis of observed collective actions about peoples thought, emotions and motivations, shows the uniformity and regularities in complex human communication in 2channel.