Mobile network creates an environment that is convenient with fast communication and no localization restriction in which it is a perfect network environment for mobile commerce websites in developing business information applications and services. Two Shopping Malls also launched many mobile commerce website services to capture the gradually growing market. Depending on how convenient and fast these services that the website provides consumers, the quality of these services will determine the consumers’ decision to leave or stay on the website, and the usability of the website will be their deciding factor. This study reviewed how a website with better usability that offers consumers high efficiency and effectiveness with the ease of learning and memorizing have a strong influence over the buying behavior of consumers. This study used experimental questionnaire method to evaluate the usability in different Shopping Mall websites. Before the experiment, this study analyzed what would the expected processes and problems would be for these websites. After the experiment, this study compared the data retrieved from the questionnaires with the experiments of actual problems. The results showed that the psychology in the questionnaire and the physiology in the real-life situation of subjects corresponded with each other. In the usability guidelines, there are significant differences between Two Shopping Malls in the area of effectiveness and learning abilities. After the cross examination of the speculated expectation of the processes and problems on these websites with the actual problems in real-time, the results showed top three issues that were found on second Shopping Mall’s " Registration Process" played huge influences on the consumer’s behavior. This study proposed various ways of website improvements for better usability after analyzing the problems resulted from poor user interface design with the services provided on this website.