The main goal of this study is to investigate moderating effects of product heterogeneity on online consumer behavior. It is hypothesized that relationships between shopping motives, emotions, and behavioral intention of online consumers that shop for agro products (high product heterogeneity) must be different from those of consumers who shop for regular industrial products (low product heterogeneity). A literature review supports this hypothesis, providing theoretical background that the perceived risk increases when consumers shop for high heterogeneity products). A structural equation model was proposed and examined through survey research. Data was collected from customers of two leading B2C e-marketplaces in Korea (N=279). One sub-group of the sample was the low-heterogeneity-product purchasing group, and another one was the high-heterogeneity-product purchasing group. Moderating effects of online product heterogeneity in the model were investigated. The findings show that product heterogeneity has a strong influence on online consumer buying behavior.