E-learning system is one of technology that can increase the competitiveness of STMIK Mikroskil. E-learning system usage will be less than optimal if students refuse or cannot use the system. Therefore, an understanding of student acceptance behavior toward the system is also important in order to improve online learning environment. This study measures the acceptance of e-learning system using the extended Technology Acceptance Model (TAM). This study aims to determine the relationship between self-efficacy, subjective norm, and experience as exogenous constructs to perceived ease of use and perceived usefulness as endogenous construct followed by testing to determine the relationship between perceived ease of use and perceived usefulness toward behavioral intention to use on e-learning system usage in STMIK Mikroskil Medan. Questionnaire data was collected from 354 active students and analyzed with structural equation modeling (SEM) using AMOS 24. The result of this study showed that self-efficacy, subjective norm, and experience has significant positive effect on perceived ease of use. Perceived ease of use has significant positive effect on perceived usefulness. Perceived usefulness has significant positive effect on behavioral intention to use, but perceived ease of use has no significant effect on behavioral intention to use. This finding improves the understanding of student acceptance behavior toward e-learning system that can help improve the service of STMIK Mikroskil e-learning system and can be used as reference for doing other similar research.