The Internet has grown at a remarkable pace since the emergence of the World Wide Web in the early 1990s. While electronic commerce (e-Commerce) has become an important issue with the growth of the Internet, there has been insufficient empirical research concerning its adoption by Internet users. In this paper, we propose the e-Commerce Adoption Model (e-CAM), which attempts to examine important factors that predict a consumerís online purchasing behavior. e-CAM integrates the technology acceptance model with the theories of perceived risk to explain the adoption of e-Commerce. Specifically, we examine the impact of the following factors on the consumerís purchasing behavior: perceived ease of use, perceived usefulness, perceived risk with products/services, and perceived risk in the context of online transaction. We test the e-CAM model using the structural equation modeling technique. Most of the causal relationships between the constructs postulated by our model are well supported, accounting for 33.4% of the total variance in e-Commerce adoption. In sum, our study finds that all of the antecedent constructs directly and/or indirectly affect the consumerís adoption of e-Commerce. Therefore, the findings suggest that firms providing products/services through e- Commerce should consider these contextual factors in order to facilitate consumersí adoption behavior.