Marketing strategies implemented during event marketing are still regarded the best offer according to consumers, thereby stimulating consumer interest and prompting impulse buying. Impulse buying is a purchase decision made spontaneously without considering the long-term value of a product. Consumers in Indonesia still need help planning their purchases well, resulting in a high impulse buying rate. This research aims to explain the dominant factor that shape impulse buying at Shopee during event marketing and the implementation of marketing strategies based on dominant factor. This research uses a mixed method. Data analysis techniques using exploratory factor analysis with data collection through questionnaires and qualitative data analysis through interviews. The results showed six factors formed based on factor analysis: urgency factor, shopping satisfaction, shopping motivation, promotion, advertising, and shopping appeal. The urgency factor is the dominant factor, with eigenvalues of 6.791. Entrepreneurs in Shopee, can implement marketing strategies by providing limited offers, vouchers, discount, and hold live streams using countdown timer to trigger a sense of urgency for consumers.