本研以資料包絡分析法(DEA)針對本國銀行進行經營效率評估，以淨值、營業費用、用人費用、利息抜出、分行數目五項為投入變數，投資收入、利息收入、非利息(服務)收入三項為產出變數，並將本國銀行依照總資產、銀行特質之不同加以分類，以探討本園銀行之總經營效率、技術率與規模效率，及其在管理上之意涵。研究結果如下：(1)依照總資產分類結果顯示：四種分類銀行之經營效率有顯著差異，其中以總資產在2100億至8000億之銀行表現最好。較大之銀行經營效率並無法隨著總資產規模增加而對增加，故不見得適合用合併或是增加營運據點之手段來改善其經營效率，較小之銀行多在規模報酬遞增階段，這些銀行若要提升其經營效率報酬為首要。(2)依照銀行特質分類結果顯示：舊銀行，新銀行，制銀行，中小企業銀行，政策性之銀行這五種銀行，只有規模效率和總效率有顯著差異，且成立時間越久之銀行在規模效率上佔有優勢，但在經營技術上本國銀行並不會因為成立時間早晚或是銀行性質不同而有所差異。本研究最後提出差額變數分析，對相對較無效率之銀行，其可善之投或產出提出建議。

This paper uses Data Envelopment Analysis to evaluate the operating and scale performance of Taiwan’s local banks for the year 2000, and explores its implication for the management. The input variables include the net worth, operating expenses, personnel expenses, interest expenses and the branch number; had the output variables are investment incomes, interest incomes and fee incomes. The banks are classified by the total assets and by the bank’s special features. The results how that: (1) Four kinds of banks based on total asset have significant difference in technical efficiency, pure technical efficiency and scale efficiency. Those banks with total assets between NT$210 billions to NT$800 billions have the best efficiency performance. Efficiency measures do not increase with size for the larger banks. So merging or expanding branches may not improve performance. Smaller banks are in increasing returns to scale, and should expand for better performance. (2) Five kinds of banks based on the setting up years and target customers have significant difference in total efficiency and scale efficiency, but no difference in pure technical efficiency. And the earlier to set up the banks, the better the scale performance. We also calculate the slack variables for inputs and outputs and make suggestions for those banks that are not efficient.