Live-streaming shopping is a new shopping pattern integrating real-time commerce communication and real-time social interaction by streaming videos. The intense attempts taken by marketers trying to persuade viewers to buy products have stimulated the purchase intention of some viewers, however, generated reactance of some other viewers at the same time, such as the behavior of “watching without buying anything.” Based on the Persuasion Knowledge Model, we investigated what persuasion knowledge viewers beheld. Thematic analysis of semi-structured interviews and online comments of viewers of live-streaming shopping revealed four themes (recognition of tactics, awareness about psychological mediators, censors on tactics, clearness of coping goals) and ten sub-themes (coupon tactic, hunger marketing tactic, social influence, flow, effectiveness, manipulativeness, legitimacy, upgrading persuasion knowledge, managing self-image, and managing costs and benefits) of viewers’ persuasion knowledge about live-streaming shopping. We argued that the persuasion of live-streaming shopping might backfire since viewers’ persuasion knowledge motivated them to take responses strategically. Discussions and implications were provided, based on which researchers in live-streaming shopping can better involve prominent factors of persuasion knowledge in their analytical framework, and marketers can improve management on their persuasion tactics.