This paper explores the impact of product diversity on consumers’ online impulse purchase intentions in the context of e-commerce development, and finds that product diversity has a significant negative impact on consumers’ online impulse buying intentions. Compared with the great product diversity, consumers have higher online impulse buying willingness when they do not have many choices. Further, we found that this effect is regulated by different shopping objects (oneself vs. intimate others). At the same time, information processing fluency plays a mediating role in this effect.