As Information technology continuously grows, the Internet has become a major and popular information technology in general communication for most people. It deeply affects the interactive relationship between people via prevalence of usage. Computer -- mediate communication (CMC), the electronic information exchange using computers via communication links, is naturally becoming an integral part of work and living for moderns. A popular CMC tool "Skype" was selected in this paper. Relevant literature and related research were reviewed in this paper. The sample of 303 usable cases was gathered and Structural Equation Modeling (SEM) was applied to examine the five latent variables (perceived usefulness, perceived ease of use, social influence, media feature and attitude) and 17 observation indicators. The result showed that not only first order confirmatory factor analysis (with correlation between latent variables) and second order confirmatory factor analysis (no correlation between latent variables of first order) had the best goodness-of-fit but also the best goodness-of-fit for the observation data.