本文主要的目的在於探討企業外部融資宣告對股價的影響，研究對象為企業現金增資宣告與發行可轉換公司債宣告。研究結果顯示： 1. 於台灣股票市場，現金增資宣告對公司股價具有顯著的正向情報效果。而公司發行可轉換公司債宣告，並不能帶給投資人顯著地異常報酬。 2. 現金增資宣告對股價的正面影響，顯著大於發行可轉換公司債宣告，與融資順位理論的預期不符，尚待後續研究者進一步探討。 3. 現金增資宣告對前一天和當天股價的影響，不因增資時期之不同而有顯著差異，但是市場崩盤前宣告地現金增資，在宣告日前後各三十天的期間內累積平均異常報酬率幾乎全部為負數，而崩盤後的現金增資宣告相對期間的累積平均異常報酬率則全部為正值。有趣的發現，有待後續研究探討其成因。資金用途與對股權稀釋程度不同之現金增資宣告，對股價也有顯著差異。

The main purpose of this paper is to investigates the impact of corporate external financing announcements on stock prices. The average abnormal return (AAR) and cumulative average abnormal return (CAAR) measures are applied for the stock-prices analysis. The important findings are as followed: 1. The announcement of a cash-offered seasoned common stock issue has a significantly positive information effect. That is, common stockholders earn significantly positive abnormal returns at the day of announcement. In contrast, the announcement of a new convertible bond issue shows no significant abnormal returns around the announcement date 2. For the impact of corporate financing announcements on stock prices, the evidence that we found in this paper, is inconsistent with that expected by the pecking order theory. 3. The cash-offerred seasoned issues announced during different periods have different impacts on share prices. And also, there are significantly different impacts for issues with different fund-raising purposes and with different degrees of dilution on equity.