In recent years, information systems auditing has received considerable attention for increased reliance on IS and IT for business operations. In Korea, information system audit is gradually being implemented mainly in large audit firms. In this period of time, this study examines audit firms’ information systems audit effect upon audit hours and audit fees. Informations generated by companies are calculated through information systems. In particular, most accounting informations are computerized, making it difficult to find companies that are following manually accounting process. These changes require auditors who perform auditing tasks to understand and utilize the information system of the audited company(Bierstaker et al., 2001; Curtis et al., 2009). In other words, the auditors need to establish an appropriate auditing plan in accordance with the information system of the audited company, and the auditors are required to have the ability as professional auditor with sufficient understanding and ability to utilize various information systems and information technologies in order to increase the efficiency and effectiveness of auditing(Bedard et al., 2005). Auditing in an actual computerized environment requires an overall understanding of the computerized information systems of the audited company from the audit planning stage. Namely, it is essential to understand the degree of computerization of the company, the complexity of the information systems, and the degree of reliance on the information systems of the company’s management activities. In addition, the auditor should prepare the basis for the trust in the companies’ information systems as an audit record, and IS audit affects the determination of the scope and method of the verification audit of the balances of relevant accounts subject to the business processes related to the company’s information systems(강인준․정병무, 2016). Considering these aspects, the information systemization of the audited company, unlike the previous audits, affects audit hours and audit fees. In the case of audit hours, efficient processing of work caused by corporate computerization can reduce the time required for auditing. On the other hand, extending the use of IT applications such as ERP (Enterprise Resource Planning) may have the effect of increasing audit hours due to the emergence of new auditing risks such as information system control and computer fraud. In addition, in terms of audit fees, the introduction of new IS auditors is required due to corporate information systemization. As a result, there is a possibility that the auditor’s audit fees will increase. However, in the case of Korea, audit fees are determined in advance. Therefore, the auditor will conduct IS audit by using the IS audit specialist within the fixed audit fees category. This additional costs are also included in the fixed audit fees, so it is necessary to examine how it affects the audit fees of the auditors. In the end, this suggests the necessity of testing through empirical analysis. However, it is hard to find any studies that have examined the related contents. Therefore, this study examines the effect of auditor’s input level of IS audit on audit hours and audit fees as a response to corporate computerization. The analysis method uses multiple regression analysis and summarizes the analysis results as follows. First, auditor 's input level of IS audit showed a significant negative relation with the audit hours. This indicates that there is a possibility of shortening the audit execution time by improving the understanding of the information system of audited company and utilization of appropriate information technology. Second, The auditor’s IS audit hours have a significant positive effect on audit fees. This indicates that auditors can increase audit fees by establishing an audit plan considering the increased information system and by putting additional IS audit personnel. Third, the entire sample was divided into Big4 and Non-Big4, and the analysis was carried out. As a result, IS audit conducted by Big4 reduced the audit hours and increased the audit fees. This study is meaningful in that the auditor’s input level of IS audit was proved to have influence on audit hours and audit fees in response to the environment where enterprise information system is advanced. However, in the case of the IS audit hours used in the analysis, it was tried to exclude the noise due to the disclosure form as much as possible, but it could not be removed completely. The data disclosure period starts from 2014 and the analysis period is short It has a limit as a point.