The research explores how online reviews may influence consumers' impulsive purchase behavior and develops a research model based on the stimulus-organism-response (SOR) framework and prior research. This research proposes that online reviews may serve as stimulating cues. In specific, online reviews (review validity, review quality, review quantity, review credibility and review timeliness) may affect consumer sentiment: pleasure and arousal (organism), which further lead to consumers’ urge to buy impulsively (response). Product involvement and reviewer level are introduced to test the relationship between the variables in the model under different experimental conditions. The questionnaire method of survey and situational experiment are used to obtain data for empirical research. The testing of hypotheses along with the analysis of reliability and validity is done using statistical tools of software-SPSS and AMOS. The results show that: review validity, review quality, review quantity and review timeliness of online reviews have a direct positive impact on impulse purchase intention. Review validity is mediated by both pleasure and arousal whereas review quantity is mediated only by pleasure. When consumers buy low involvement (vs: high involvement) products and read reviews from senior (vs: junior) reviewers, online reviews have a stronger impact on impulse buying intention. This research puts forward the marketing strategies for online sellers by not only helping them carry out the method of online word-of-mouth marketing more efficiently, but also in expanding the influence of positive internet word-of-mouth and thereby promote the occurrence of impulse buying behavior of consumers.