本論文之研究目的係驗證銀行管理當局是透過盈餘平穩化，增加盈餘對於未來盈餘的訊息，抑或是操控會計數字從而降低盈餘品質。本文採用兩種指標衡量盈餘平穩化：裁決性的貸款損失準備與公允價值第二等級與第三等級輸入值。以美國銀行作為本論文的樣本標的，經由實證結果發現，盈餘平穩化程度較高的銀行其股價能反映更多未來盈餘的資訊，顯示著平穩化程度會增加銀行當期盈餘對於未來盈餘的預測能力。除此之外，本文依照銀行規模與業務特性，分別比較大小銀行;商業銀行與儲蓄機構，個別探討盈餘平穩化和盈餘資訊性間的關聯。 / This paper investigates whether bank income smoothing is due to communication of future earnings or opportunism to garble accounting numbers. I adopt two measures of bank income smoothing, i.e., discretionary loan loss provision and Level 2&3 fair value inputs. Using a sample of U.S. banks, I find that higher-smoothing banks’ current stock prices capture more information about their future earnings to a larger extent than those of lower-smoothing banks. Moreover, I separate the bigger banks from the small banks and differentiate commercial banks from saving institutions to particularly investigate the association between income smoothing and earnings informativeness.