[目的/意义］基于SOR（刺激-组织-反应）模型，探究在线健康社区中基于情绪中介机制的社会支持对用 户参与行为的影响。［方法/过程］社会支持作为“刺激”（S）因素，通过引入情绪作为个体的“机体内化”（O），研究在 线健康社区用户“行为反应”（R）机理过程。选取某在线健康社区244名用户的465 337个发帖为实验样本，使用 分层回归分析法对模型进行实证检验。［结果/结论］在线健康社区提供的信息支持、情感支持和社交支持均对用 户的参与行为产生积极影响。此外，用户情绪在社会支持与用户参与行为的关系中具有显著的部分中介效应，且 这种中介效应会受到用户性别的调节作用，即情绪的中介作用对男性用户的影响更大。

[Purpose/significance] Based on the SOR(Stimulus-Organism-Response) model, this study explored the ef? fect of social support on user engagement based on the mediating role of emotion in online health communities.[Meth? od/process] Taking social support as the "Stimulus" (S) factor and emotion as the " Organism "(O) factor, this paper studied the mechanism of users' " Response" (R).We obtained 465 337 posts by 244 users from an online health com? munity as sample data. The hierarchical regression analysis is used to test the conceptual model. [Result/conclusion] The results show that information support, emotional support and social support provided by the online health communi? ty had a positive impact on the users' engagement behavior. In addition, user emotion has a significant partial mediating effect on the relationship between social support and user engagement behavior, and this mediating effect is moderated by user gender, that is, the mediating effect of emotion has a greater impact on male users.