本研究以2007年1月至2013年12月之資料探討我國21家銀行，取其月資料，並以縱橫資料(Panel Data)的形式，用Gonzalez, Terasvirta and van Dijk（2004, 2005）所發展的縱橫平滑移轉門檻模型來進行論文研究，探討逾期放款率與銀行財務績效之的關聯性，其是否對銀行績效，產生縱橫平滑移轉效果，並針對影響銀行績效的可能控制變數，分別為備抵呆帳覆蓋率、存放比率、放款成長率作為解釋變數，進一步對銀行財務績效受解釋變數的影響做評估和衡量。 實證結果顯示:逾期放款率對銀行財務績效都存在顯著的平滑移轉效果，備抵呆帳覆蓋率、存放比率、放款成長率在各門檻間都能對銀行財務績效顯著產生不同的影響。在逾期放款率位於低檔時，適當提高備抵呆帳覆蓋率、存放比率、放款成長率對銀行財務績效是有正向效果的，然而當逾期放款率位於中高檔時，此時銀行放款品質處於惡化的狀況，這時反而對銀行財務績效產生更大的負向衝擊。 The purpose of this study is to investigate the effect of non-performing loans ratio on the performance of banks by using panel smooth transition regression model which introduced by Gonzalez, Terasvirta and van Dijk (2004, 2005). Our samples consist of 21 Banks during the period of 2007 to 2013.Indicators like return on assets and return on equity are used to measure the financial performance. This empirical study will apply non-performing loans ratio as transfer variables. Furthermore, it uses loan loss coverage ratio, loan to deposit ratio and loan growth rate to estimate how these variables influence the performance of banks. The empirical result proves that there exists a nonlinear relationship on non-performing loans ratio as transfer variables. When non-performing loans ratio under the threshold, loan loss coverage ratio, loan to deposit ratio and loan growth rate have positive correlation with the performance of banks. However, when non-performing loans ratio over the threshold, loan loss coverage ratio, loan to deposit ratio and loan growth rate have negative influence to banks performance.