雖然國外有許多探討分析師盈餘預測偏差文獻，然現有國內外文獻，尚無探討當證券分析師所屬銀行控股公司之商業銀行與所追蹤銀行控股公司之商業銀行與分析師為競爭者時，分析師對其競爭商業銀行盈餘預測之行為。本研究之目的在於探討（1）追蹤競爭商業銀行分析師與其他未追蹤競爭商業銀行分析師，其盈餘預測是否比較公正？或比較正確？（2）當分析師追蹤競爭商業銀行時，盈餘預測修正次數是否比較頻繁？（3）當分析師追蹤競爭商業銀行時，其盈餘預測修正對公司股價影響為何？ 本研究研究結果顯示，追蹤競爭商業銀行證券分析師與其他未追蹤競爭商業銀行分析師的樂觀預測偏差有顯著差異。在2001年與2004年，追蹤競爭商業銀行證券分析師之預測錯誤顯著低於其他未追蹤競爭商業銀行分析師，然而，在修正次數部分，追蹤競爭商業銀行證券分析師與其他未追蹤競爭商業銀行分析師並無顯著差異。此外，追蹤競爭商業銀行證券分析師與其他未追蹤競爭商業銀行分析師預測修正對股價影響並無顯著差異。 Although analysts’ forecast behavior has been the focus of recent studies, there remains a question as to the forecast behavior of an analyst who works for a specialized investment bank subsidiary of the bank holding company and follows her competing commercial banks. The purpose of this study is to investigate whether the forecast bias and accuracy are different between analysts who follow competing commercial banks and analysts who do not follow. We also investigate that whether analysts who follow competing commercial banks revise their forecasts more frequently than others. Moreover, this study will examine the stock price impact of analysts’ forecast revisions. The empirical results indicate the forecasts biases made by the analysts who follow the competing commercial banks are significantly different from those made by the analysts who do not follow. The forecast errors made by the analysts who follow the competing commercial banks are significantly lower than those made by analysts who do not follow in 2001 and 2004. However, the number of revisions is not significantly different between analysts who follow the competitors and those who do not. The market does not react strongly to forecasts revisions made by analysts who follow their competitors.