Business models of e-commerce which have been successfully applied in a developed society do not always guarantee success in other environments where the degree of IT availability differs. This is due to the difference of culture, systems and technological basis among the countries. This study aimed to compare e-commerce system acceptance in countries with different environments and to identify the determining factors for the acceptance of e-commerce. The result shows that, in order to make e-commerce easily accepted in countries with different IT environments, factors such as trust, reputation and usefulness should be addressed more sincerely in the business strategy.