本文旨在以債權人的觀點，針對2008 年至2011 年在臺灣證券交易所及櫃檯買賣中心交 易之上市（櫃）公司為研究樣本，探討上市（櫃）公司購買董監事暨重要職員責任保險 （簡稱D&O 保險）是否會影響債權人對企業信用風險的認知，而債權人對企業信用風 險的認知係以信用評量機構發布的評等來衡量。整體而言，實證結果穩健地支持相對於 未購買D&O 保險的公司，有購買D&O 保險的公司，其信用評等較佳；然而進一步針 對有購買D&O保險的公司，探討其投保金額與信用評等之關聯性時，實證結果則發現， 當公司依自身之特質及所面臨的風險投保適度的金額（即正常投保金額），將可獲得較 佳的信用評等；但當公司投保金額超過公司自身特質及風險所需之保險金額（即超額投 保金額）愈大時，反而使債權人認為董監事與管理階層的道德風險會增加，因而導致給 予較差的信用評等。

This paper explores the effect of directors’ and officers’ liability insurance (D&O insurance hereafter) on the firms’ credit ratings, which serve as a proxy for firms’ credit risk perceived by the creditors. We construct a sample from the firms listed on both the Taiwan Stock Exchange (TWSE) and GreTai Securities Market (GTSM) from 2008 to 2011. The evidence shows that firms with D&O insurance have better credit ratings than those without D&O insurance. Further results show that D&O insurance coverage also impacts firms’ credit ratings. If the firm purchases the appropriate (normal) D&O insurance coverage that suits the firm’s specific characteristics and risk, it tends to have a superior credit rating. However, if the firm purchases excess (abnormal) D&O insurance coverage that is more than the firm’s needs, it tends to have an inferior credit rating, a fact that likely stems from opportunistic behaviors from the directors and managers at the expense of creditors.