本研究旨在探討企業盈餘管理行為對其信用評等之影響，以Ordered Probit Model，探討台灣上市櫃(包含興櫃)企業之盈餘管理行為，對台灣經濟新報社(TEJ)的台灣企業信用風險指標(Taiwan Corporate Credit Risk Index, 簡稱TCRI)是否造成影響，並進一步觀察其影響為何。 本研究發現，企業之盈餘管理行會影響其信用評等，而且透過進一步之邊際影響分析，顯示企業盈餘管理對當期盈餘之影響，與信用評等之間存在著反向的關係，意味著，信用評等人員在使用財務報表，進行信用評等程序時，統計上會因為企業之盈餘管理行為而有處理上之差異；本研究另外發現就平均而言，盈餘增加(減少)之裁量性應計數影響TCRI下降機率的增加(減少)幅度，大於TCRI不變以及TCRI上升之機率變動幅度。 / This study investigates the influence of earnings management on credit rating. Using Ordered Probit Model, this study tests whether earnings management of listed companies (emerging stock included) effects Taiwan Corporate Credit Risk Index (TCRI). This study finds that earnings management does affect credit rating. In addition, it suggests that earnings with income-increasing discretionary accruals have more opportunity for getting downgradings than earnings with income-decreasing discretionary accruals through analysis of marginal effects. That is, the credit analysts treat earnings management in a different way when rating companies. Moreover, this study also finds that the marginal effects of income-increasing discretionary accruals of increasing opportunity for getting downgradings are larger than the marginal effects of opportunity for getting unchanged and upgradings. Similarly, the marginal effects of income-decreasing discretionary accruals of decreasing opportunity for getting downgradings are larger than the marginal effects of opportunity for getting unchanged and upgradings.