信用評等機構對於企業與市場投資者而言有著重要且無可取代的功能，其所提供之信用評等資訊應當是許多市場投資者所仰賴的重要決策依據，但近年來，卻有許多外界聲浪質疑信評機構評等之準確性，本論文之研究目的即是希望從錨定效應此一行為偏誤之觀點切入，探討國內信評機構在對企業評等時，是否會受到錨定效應影響，導致評等調整不正確或是評等落後其他財務指標等現象發生。 研究結果顯示，國內信評機構對受評企業之過往財務資訊存在錨定現象，但不至於大幅影響整體違約風險之準確性，且信評機構對受評企業財務之惡化較為敏感。另一方面，本研究也發現，信評機構對於非上市櫃公司、金融業以及初次評等等級在「twAA」以上企業之評等，存在較為明顯之錨定現象。 / Credit Rating Agencies (CRAs) play a major role in the financial market. Credit rating purport to provide investors with valuable information they need to make decisions about investing, but the accuracy of the rating itself has been called into question by many investors in recent years. The purpose of this study is to examine the anchoring effect on CRAs while the rating is being given. The results indicate that domestic CRAs tend to be anchored on the past financial information of the issuers. But the impacts are very slightly. Besides this, CRAs seem relatively sensitive to the financial deterioration. Moreover, the anchoring effect are much more significant when the debt issuers are private firms, financial institutions or the companies with greater or equal to twAA initial credit rating.