This research sets out to determine factors that influence consumers’ adoption of B2C E-commerce in Macao. While prior research has shown that there are many factors that influence E-commerce adoption, this research hypothesized that two variables – namely, trust and willingness to use credit cards for online transactions – influence E-commerce adoption in Macao. This research further hypothesized that trust and willingness to use credit card interact to influence adoption. Using data collected from a questionnaire survey, the results of this study found that the two hypothesized variables are positively related to intention to adopt E-commerce. The results also support the interaction effect. The nature of interaction showed that trust is related to E-commerce adoption only when willingness to use credit card for online transaction is high. Also, willingness to use credit card for online transaction is related to E-commerce adoption only when the level of trust is high. These results provide a richer understanding of the relationship between the hypothesized variables and Ecommerce adoption. This study also collected interview data related to Internet users’ adoption of E-commerce. The interview data provide a better understanding on why Macao people are afraid of using credit card for online transactions. The researchers gathered more information about interviewees’ credit card usage and habits, their attitudes toward credit card security, and their thoughts regarding identity theft. The interviews also uncovered other factors that may influence E-commerce adoption.