In the information age, more and more people are buying products on the Internet. Impulsive buying within the online shopping research is gradually receiving more attention, as it contributes significantly to online retail profit. This study proposed a research model based on the Stimulus Organism Response (S-O-R) framework to finding the antecedents of consumer reaction and behavior, specifically to distinguish task-relevant stimuli (price attribute and convenience; i.e. TR cues) and mood-relevant stimuli (visual appeal, social influence, vendor creativity; i.e. MR cues), perceived usefulness and perceived enjoyment to explore which factors affect online impulse buying behavior. Data from 446 customers who bought apparel products online were collected to evaluate the research model. The results indicate that convenience, visual appeal, social influence, and the vendor's creativity have a positive impact on perceived usefulness; price attribute, visual appeal, social influence, and the vendor's creativity have a positive impact on perceived enjoyment. The results also indicate that convenience and social influence are the two strongest predictors of perceived usefulness and perceived enjoyment respectively. Also, it was observed that impulse buying tendency and perceived enjoyment both significantly affect consumers’ urge to buy impulsively, whereas perceived usefulness indirectly influences consumers’ urge to buy impulsively through perceived enjoyment.