With the context of the social crisis (COVID-19), I examined how online community participants’ participation behaviors (informational, emotional support and companionship behavior) affect original posters’ (OP) emotions regarding their emotional issues. And whether these behaviors are related to the overall effectiveness of user participation in the online community. To answer these questions, I developed a conceptual framework based on the affect theory of social exchange. Textual data is collected from one subreddit (r/Covid19_support) and the text mining method is applied to generate measures of constructs in the model. The hypotheses are tested with logistic regression method and the correlation test. The preliminary results indicate that online users’ emotional support and information support behaviors can help to alleviate OPs’ emotional issues during the pandemic. With mixed level measures, I found OPs’ positive emotions are positively related to the effectiveness of user participation behaviors in the online community. The hypothesized positive relationship between companionship behavior and an OP’s positive emotion is not supported by analysis results. These findings enhance our understanding about the value of user participation and its overall effectiveness in online communities. It also brings more insights to examining online communities’ social value in the context of social crisis.