Information system audit of Korea is different from that of the United States of America, Japan and so on. Information system audit improves the quality of information system. Information system audit of Korea carried out administrative branches. Recently Public sides required ordinary audit frequently. The reason is that the risk of information system project has increased. Examined closely relation between audit quality and audit style such as ordinary audit, fixed period audit, residence audit, and responsibility audit. And, wished to examine closely relation between audit quality and customer satisfaction. As research result, being effect factor that audit style keeps in mind in audit quality, also, audit quality in audit satisfaction, and was proved that exert effect that ordinary audit, report to the responsibility audit or sense of responsibility state keeps in mind in audit satisfaction.