Impulsive buying behavior is an important aspect of consumer behavior and is of significant interest to researchers and retail management alike. It is a familiar from of in-apparel store behavior because of its social-psychological characteristics. The objectives of this study were to find out the variable(5) influencing impulsive and non-impulsive buying behavior, as well as to investigate the causal relationships between variables related to impulsive buying behaviors in boutiques. A questionnaire was completed by 345 boutiques customers in Busan, Korea. Demographics showed that consumers were more educated and had higher incomes than average consumers in Korea. Data was analysed by discriminant analysis and path analysis. Results showed that "Clothing involvement" was the most influencing variable determined impulsive buying behavior. "Self-monitoring" proved negatively influencing on impulsive buying behavior in boutiques. Consumers with low interest in apparel reacted positively to the in-store purchasing situation, and did negatively to their affective factors. As a result, they provided the useful information for consumer behavior researchers and boutiques retailers.