稽核制度一向被視為係解決或減輕資訊不對稱所衍生之代理問題的重要工具。惟稽核人員能否保持絕對的超然獨立？在屢次的歷史教訓中，答案似乎是否定的。因此，使用一個非獨立的稽核人員以執行必要的稽核任務，遂成為主理人不得不面對的一項現實。本研究透過稽核人員「潛在的聲譽損失」將影響其獨立性 (或誠實度) 的假設，運用分析性研究方法，探討在僅能使用「非獨立稽核人員」的前提下，主理人應如何制訂其最適的稽核政策。在本研究之模式設定下，所獲致的重要結論包括：使用完全不誠實型之非獨立稽核人員，將無法產生經濟租擷取 (rent extraction) 的效果；且在其他條件不變下，景氣 的好轉、稽核品質的提昇、或懲罰金額的增加，均可能導致主理人使用非獨立稽核人員之最適機率的降低。

Audit system has been considered one of the important mechanisms to eliminate or mitigate the moral hazard coming from information asymmetry. However, the independence of an auditor becomes a key issue once the principal decides to employ the audit system. The paper presents a model to study the audit policy of the principal under continuous states. Specifically, the study considers the potential collusion between the manager (the agent) and the auditor (the monitor). By classifying the auditor as one of the following types, i.e. absolutely honest type, generally honest type, and absolutely dishonest type, we derive the optimal audit decisions under various states while the principal can only use non-independent auditors, i.e. the latter two types of auditors.