The paper interprets the mechanism of word - of- mouth information chain dissemination in online com- munity based on the deeply excavation of trust theory. Firstly, it makes a definition of word - of - mouth information chain dissemination in online community and analyses its basic chain structure. Then it explains the connotation of the trust in online community, and proposes its effect on the developmen! of the basic chain structure which will genetate three kinds of chain structure : basic chain, derived chain and initiative chain. Thirdly...