本文的主要探討國內八家公股行庫對3D1S產業放款集中度與經營績效、逾放比之關係。本文首先求出八家公股行庫對3D1S產業之放款集中度，再利用縱橫迴歸模型探討3D1S產業放款集中度的高低與公股銀行逾放比的關係及對公股銀行經營績效的影響。實證結果發現，3D1S產業放款集中度會影響銀行的經營績效及逾放比，且呈現顯著的正向關係；備抵呆帳覆蓋率與銀行經營績效呈現顯著的正向關係；存放比率對逾期放款率呈現顯著的正向關係；資產規模與淨值報酬率、逾期放款率呈現顯著的正向關係，表示銀行規模愈大，能夠貸放出去的金額相對較高，收取利息的收入高致銀行獲利能力愈好，但放款發生呆帳的機會也愈高。

The article tries to explore the relationship between loan concentration and business performance, NPL of eight domestic public shares of banks which loan to 3D1S industries. In empirical study, we firstly obtained the loan concentration of eight banks to the 3D1S industries, then apply the panel regression model to discuss the relationship between loan concentration and business performance, NPL, respectively. The empirical results show that loan concentration of 3D1S industry has a positive significant effect on the bank's business performance and the NPL ratio. This means that the loan concentration does help to improve return of asset (ROA) and return of equity (ROE). However, the loan concentrated in certain industries will result a high credit risk concentration and relatively high NPL ratio. The allowances for bad debts and business performance show a significant positive relationship. It implies that the better quality of bank assets, the better business performance. The loan-to-deposit Ratio and NPL ratio presents a significant positive relationship, which means that higher loan-to-deposit ratio, the chance of occurrence of non-performing loans may be greater. Whereas the scale of asset and return of equity (ROE), NPL also shows a significant positive relationship, which implies that when the scale of bank is larger, will has a relatively high amount of loan and interest income, respectively. It will cause a relatively higher chance of bad debt.