IS audit has been regarded as contributing to the improvement of the quality of information Systems, recently, it has been argued that it is not possible to expect a effectiveness, because it can offset the schedule burden due to the preparation of additional documents for Audit and it affect to the project schedule. The effectiveness and quality criteria of IS audit are different between groups, because IS audit is responsible for checking the results and process of the developer company. In this study, we modeled between IS effectiveness and auditor competence, audit firm competence, IS audit standards. As a result, it was concluded that auditor competence, audit firm competence, IS audit standards have a positive effect on IS audit effectiveness. However, according to the result of comparing between interest groups, audit firm competence and audit standards were significant in auditor group, but audit standard was significant in requesting organization and developing company thought that auditor was a important factor to audit effectiveness.