The importance and demand about IS(information system) audit we increasing to raise quality of IS and prevention of the IS risk and dysfunction. Technology and system research for the substantiality and raising reliability of IS audit are continuously performed. But, there are misunderstanding of audit clients about IS audit, insufficiency of auditor`s ability and misunderstanding of new technology and target business area. Therefore, is not getting trust from client or system integrator because service quality of IS audit is weak relatively. This study aims at survey correlation between audit service quality factor and audit quality, between audit quality and customer satisfaction. The results of this study are as follow. Auditor`s ability, correspondence has a significant effect on audit quality, also audit quality on audit satisfaction, and Auditor`s ability, reliability has a significant effect on audit satisfaction.