The phenomenon of Korean brand ambassadors (Hallyu) has been identified as one of the most effective marketing strategies to increase sales, specifically in e-commerce. Fans of these celebrities do not hesitate to buy products promoted by Hallyu repeatedly and in a high amount as the devotion to their idols. The attractiveness of Hallyu predicts can stimulate consumers hedonic motivation, a shopping motivation driven by fulfillment of emotional or other subjective needs. This motivation then leads to impulsive buying behavior, unplanned buying due to sudden desires. E-commerce enjoys the benefit of impulse buying phenomena because consumer buying process occurs easily. It is different from other buying behavior which usually takes time because consumers need to consider their choices carefully. This research aims to identify the relationship between brand ambassadors, hedonic shopping motivation, and impulsive buying behavior, with fanaticism predicts to moderate the relationship between brand ambassador and hedonic shopping motivation. Using a technique of purposive sampling, 160 samples have been selected from Jabodetabek and other areas, age 19-25 years, the fans of Hallyu and actively shop in e-commerce. Partial Least Square has been used to analysis the data. Result of this study demonstrates that attractiveness of brand ambassadors significantly influences consumers' hedonic shopping motivation and impulsive buying behavior, without fanaticism serve as the moderation factor. This finding provides valuable insight for e-commerce, which targets young consumers, on how to optimize the use of brand ambassador to stimulate consumer buying behavior.