本研究旨在探討承銷業務對中國證券分析師於承銷前所發佈之盈餘預測準確性與樂觀偏頗預測之影響,並探討不同投資人對於證券分析師所發佈之樂觀盈餘預測是否能洞悉並調整其偏誤。 實證結果顯示,於中國並未發現顯著的證據證明承銷商所屬證券分析師在取得承銷業務之前,對所有研究公司之盈餘預測正確性較高。同時本研究也發現,發布盈餘預測報告日離盈餘宣告日越近,盈餘預測就更準確。此外,在承銷商取得承銷案前60天與前90天,並未發現承銷商所屬分析師策略性於承銷商取得承銷案前發佈樂觀偏頗預測。另一方面,在中國,機構投資人持股比例高之股票受到分析師樂觀偏誤盈餘預測影響程度大於機構投資人持股比例低股票。 This study aims to examine whether underwriting business in China would have influence on analysts’ earning forecasts before their investment banks win the underwriting mandate. This study also examines whether analysts may strategically issue optimistic biased forecasts before a company decides the underwriters before 60 days. Furthermore, we examine whether different investors could understand analysts’ biased forecasts and make adjustments in the optimistic earning forecasts. The empirical results reveal that there is no significant evidence to prove that affiliated analysts would issue more accurate earning forecasts than unaffiliated analysts before the company decides the underwriter. However, we find that affiliated analysts seem not to issue optimistic-biased forecasts strategically 60 days and 90 days prior to the date of deciding underwriter. In addition, optimistic-biased forecasts have larger impact on those stocks with higher institutional investors holding than those with lower institutional investors holding.