本研究以Ordered probit 模型，探討信用評等與盈餘管理之關聯性。研究樣本以台灣經濟新報資料1997 年至2002 年之上市、上櫃公司，不含金融業，並剔除IPO 與當期現金增資之企業資料，共有完整信用評等與財務年資料2,892 筆。 在研究期間，企業之信用評等有相當大的變化，影響信評之盈餘管理項目也有變動。研究發現信用評等較佳者因擁有較多資源，透過長期盈餘規劃以影響信用評等；信用評等較劣者，多試圖操作當期盈餘管理項目以彌補當期盈餘。企業若企圖維持原有信用評等，則盈餘操縱之範圍擴大。 本研究特別單獨探討電子業，因其為台灣目前經濟發展之重心。發現其信用評等表現略優於其他產業，較注重長期資源規劃，與其他產業中信用評等較佳者的盈餘策略相同。

We utilize Ordered Probit Model to explore the relationships between credit ratings and earnings management for all Taiwan public holding companies from 1997 to 2002, except for the banking and insurance industries. During our study period, credit ratings changed a lot for most firms. We find the relationships between credit ratings and the accrual accounting items for earnings management. Firms with better credit ratings tend to use long-term accrual items for earnings management; on the other hand, firms with inferior credit ratings use current accrual items to manipulate earnings. We also find that if the firm tries to maintain its credit ratings level, it would use more accrual items for earnings manipulation and credit ratings. Our findings indicate that the average credit ratings of electronics manufacturing company are better than rest of our studied sample firms. This implies that electronics manufacturing firms, along with other better credit rating firms, have the tendency to focus more on long-term than short-run.