Abstract: 【Purpose/significance】Under the boom of online health information communication, the vertical interaction in mass social
media and vertical online health communities provide users with a plenty of online health information communication channels.
Deeply exploring users' participation driving factors will help users expand health information communication channels, and optimize
the support of diverse communities to online health communication.【Method/process】By collecting the texts sent by users in super?talk of depression disorder in Weibo, this paper analyzed and extracted concepts and categories based on grounded theory, and then
built the model of users' participation driving factors in mass social media.【Result/conclusion】This paper reveals the users' partici?
pation driving forces for depression disorder topic includes, spiritual needs, the motivation of adjuvant therapy, and the motivation of
help. In addition, the differences between online communities will lead to the differences in text types sent by users, as well as the dif? ferent participation driving forces. It may further influence users' choices when using online communities with different purposes.【In?novation/limitation】This article emphasizes the users' participation driving factors in online health communication in mass social me? dia, and additionally compares the results with vertical online health communities. The further research can continue to explore the be? havior differences with more types of online communities.