The objectives of this study, are: 1) To find out the impacts of the ease of using information technology toward the interest of using online trading site (case study on the users of “Z” trading site) and 2) To find out the impacts of the benefit of using information technology toward the interest of using online trading site (case study on the users of “Z” trading site). This study is used quantitative method, which the data collected are in the form of statistics with the population of the study are the users of “Z” online trading site. The data analysis that is used in this study is the analysis of multiple linear regression. The results of the study showed that a belief is influencing toward the use of online trading transaction system to Z's costumers, thus it can be said that, as is the enhancement of a belief then it can increase the use of online trading transaction system to Z's costumers. “Z” is also the trading site which gives satisfaction guarantee to the costumers, so that it can support the costumers to do online transaction. A belief and satisfaction are influencing simultaneously toward the use of online trading transaction system to Z's costumers.