Corporate governance includes internal control and risk management. These two factors will be assessed in the external audit. External audit plays a monitoring role. External auditors must identify internal control systems and risks and evaluate them. As mentioned above, if a company has good internal control systems, external auditors may rely more on control tests and therefore perform less substantive tests. Conversely, if internal control is inadequate, auditors must perform more extensive substantive testing that requires more audit time. Therefore, good corporate governance can help reduce audit work and time and improve audit quality as resources are used efficiently. Risk-based audit focuses more on high-risk aspects and less on low-risk ones. To have a more accurate risk assessment, auditors must have a clear understanding of the company, business and industry environment, internal control systems, management's response attitude towards risk (Holm and Laursen, 2007). Therefore, external auditors help shareholders to have a better understanding of the