本研究主要在探討臺灣上市公司年度盈餘資訊的揭露對股價的影響。由於國內先 前的研究都將年度實際盈餘及年度盈餘預測分開來探討其與股價的關連性，因此 本研究擬結合上述兩盈餘資訊，即選取同時公告前一年之年度財務報表及當年度 財務預測的上市公司為樣本，探討兩盈餘資訊同時公告的情形下對股價的影響， 且為了評估此一事件的適切性，本研究亦探討公司管理當局原始財務預測、實際 盈餘公告前之最後一筆分析師盈餘預測與天真模型（Naive Model）下之盈餘預 測三者間之準確度比較。 實證結果顯示： 一、三者問的準確度依序為分析師盈餘預測、管理當局原始盈餘預測、天真模型 下之盈餘預測。 二、實際盈餘資訊及管理當局盈餘預測資訊均為好消息的公司，雖然公司帶來雙 重利多，但其所公告的盈餘資訊卻不具資訊內涵，僅造成股價的小幅變動。 三、實際盈餘資訊為好消息，管理當局盈餘預測資訊為壞消息的公司，其所公告 的盈餘資訊具有資訊內涵，且標準累積異常報酬呈現顯著的負值。 四、實際盈餘資訊為壞消息，管理當局盈餘預測資訊為好消息的公司，其所公告 的盈餘資訊不具有資訊內涵，但標準累積異常報酬呈現負值。 五、實際盈餘資訊為壞消息，管理當局盈餘預測資訊亦為壞消息的公司，其所公 告的盈餘資訊具有資訊內涵，且標準累積異常報酬呈現顯著負值。

　　　　　This study examines the effect of annual earnings announcement on the stock price in Taiwan. There are many studies focusing on this issue up to now. Unlike prior studies which examine the effect of actual earning announcement and earning forecast on stock price separately, this paper selects the sampling companies which announce actual earnings of the year before and forecast the earnings of the forthcoming year at the same time. Our results show that: 1.The predictive accuracy of the three groups is as follows (from the best to the worst): analysts' forecast, management forecast, and the naive model. 2.There is no information content for the companies which report good news both on actual earning and earning forecast. Their announcement only causes small effect on stock price. 3.There is information content for the companies which report good news on actual earnings and bad news on earning forecast. Their standard accumulated abnormal return shows a significant negative value. 4.There is no information content for the companies which report bad news on actual earning and good news on earning forecast. Their standard accumulated abnormal return shows a negative value, but not significant. 5.There is information content for the companies which report bad news both on actual earning and earning forecast. Their standard accumulated abnormal return shows a significant negative value.