As a new form of e-commerce, live streaming commerce can easily drive consumers to buy impulsively in a short period of time, which brings significant benefits to business. By applying Aristotle’s rhetoric appeals, we define the concept of e-commerce live streamer’s persuasive ability and distinguish its four dimensions, i.e., logic, expertise, morality and emotional contagion. Based on S-O-R paradigm, our study constructs a theoretical model to investigate how live streamer’s persuasive ability influences impulsive purchase behavior in live-steaming commerce. The results demonstrate that four dimensions of live streamer’s persuasive ability has varying degrees of impact on consumers’ affective reactions, i.e., affective trust and perceived pleasure, which in turn leads to their impulsive buying intention. This investigation provides both theoretical implications for the literature of live streaming commerce and practical implications for e-commerce live streamer.