本研究旨於探究海峽兩岸經濟合作架構協議（Economic Cooperation Framework Agreement, ECFA）對「回流臺商」之股價效應，以具代表性之「回流臺商」－康師傅控股為研究對象，採事件分析法，以三個重要相關事件日實証驗證ECFA對康師傅控股之臺灣及原上市地（香港）之股價效應。研究結果顯示，ECFA之簽訂對康師傅控股之臺灣及原上市地（香港）股價之效應大抵一致。香港股市與臺灣股市於ECFA第三次協商時（事件日一）皆給予康師傅控股顯著正面評價，且香港股市之反應較臺灣強烈，顯示兩市場於此事件日前後皆一致看好康師傅控股之「後ECFA時代」之前景；而於ECFA簽訂後、立法院三讀通過（事件日二）前，由於朝野共識之不足而使兩市場在信心不足下，皆出現擔心協議無效之顯著負向反應，但臺灣股市於三讀通過後立即回正，顯示投資人於此時仍樂觀看待ECFA簽訂後之康師傅控股的經營績效；最後，臺灣股市於ECFA正式生效（事件日三）後，因未見事前預期之效應，乃修正過度樂觀之態度，轉予康師傅控股顯著負向之評價，而香港股市於ECFA正式生效（事件日三）後，卻轉而呈現不顯著之結果，顯示第三個事件日因接近前一事件日，香港股市對此事件已於前一事件日反應完畢，但此結果亦可能顯示香港股市中有相當比例之投資人，如臺灣投資人般認為成效未如預期，因此修正先前過度樂觀之評價，造成正反面力道勢均力敵，使其股價未呈現顯著異常報酬。

This study purposed to take Tingyi (Cayman Islands) Holding Corporation as the representative sample to investigate the ECFA effects on homecoming Taiwanese enterprises stock prices at three relevant event days by employing Event Study Analysis. To be complete and comparable, this study examined Tingyi stock prices in Taiwan and Hong Gong stock markets simultaneously. Results showed that ECFA effects on stock prices of Tingyi Holding Corporation is quite accordant in Taiwan as well as in Hong Kong (original listed place). Both markets showed significant positive assessments during the third consultative meeting of ECFA (event day 1), Hong Kong stock market in particular. It revealed that these two markets are all optimistic about the prospects for the ”post-ECFA era”. However, before the agreement has gone through the entire three-reading procedure in the Legislative Yuan (event day 2), the opposition threatened to boycott the procedure, which led to the lack of confidence and the two markets showed the negative reflects due to the concern of the invalidity of the agreement. Though, Taiwan stock market showed positive reflect immediately after the three-reading procedure, which means that investors remained optimistic attitude to the operating performance of Tingyi after the signing of ECFA. Finally, Taiwan stock market corrected its' over-optimistic attitude toward Tingyi Holding Corp. after ECFA becomes effective officially (event day 3), while Hong Kong market showed no significant effect after the agreement becomes effective.