近年來，在台灣金融機構發展過程中，我們發現無論是銀行業者、保險機構或是地方信用合作社等金融機構，對於其經營績效衡量主要都偏向於實體市場，如實體通路數（分行）是否增加﹖市占率規模是否擴大﹖換言之，分行家數的擴張似乎成了銀行開疆闢土的實體展現，然而電子金融市場持續成長下，金融機構不在只是擴充分行為其必要的手段，現階段若要吸引新客戶，降低作業成本，快速達到此目的的不二法門便是發展網路銀行，利用網路這個成本低，投入成本不高，24小時皆可以服務客戶的特性下，網路通路的發展反而變為金融機構兵家必爭之地。然而持續不斷的投入網路資源對會提升公司整體績效嗎？快速成長的網路銀行是否會因為擴充太快卻導致營業及人事成本的增加，台灣市場的銀行家數已趨於飽和的狀況下，本文將以全國銀行業中之三十二家銀行為研究對象，探討其由網路銀行的推廣，其對於經營績效ROE、ROA之影響。 In recent years, under the development of financial institutions in Taiwan, We found that, no matter for banking industry, insurance agencies, local credit unions or other financial institutions, the number of physical channels and the scale of market share seem to be the important criteria for the measurement of their business performance. In other words, the expansion of the number of branches seems to be a progress for their market share. However, under the fast growing electronic financial markets, to expand the branches of the financial institutions is not the way to attract their new customers and to lower their operating cost. The appropriate way to fast achieve the goal of attracting customers and reducing costs is to develop Internet banking. Owning to the low cost of Internet system and the 24-hour service characteristic, the network access system seems to be the strong desire of the financial institutions for their operation and development. However, will the continuing investment in network resources improve the overall performance? The rapidly growing of Internet banking might lead to the increase in the operating and personnel costs. Under the phase of the saturated condition that Taiwan’s banking system if over-banking, we are trying to investigate whether the expansion of the internet banking will improve the bank’s operating performance. The aim of this study is to investigate the effect of the internet banking on the bank’s operating performance of ROA and ROE using sample data of 32 banks of Taiwan.