股利與股票購回都是公司採行的盈餘分配方式，有些文獻用資訊信號假說以及自由現金流量假說解釋其宣告效果。鑑於股票購回已實施數年，本文欲探討股票購回是否會影響股利政策變動的宣告效果，以了解股票購回是否為現金股利的替代政策。研究結果發現，股票購回會增強股利增發的正面宣告效果，並緩和股利減發的負面宣告效果，而且，股票購回對現金股利變動宣告效果的影響較其對股票股利的影響大。此外，資訊信號假說、自由現金流量假說以及公司規模對於股利政策變動的宣告效果都有解釋能力，尤其是在價值股時最為明顯。

Since both dividend and stock repurchases are ways corporate to pay, some studies explain the announcement results by information signaling and free cash flow hypotheses. The stock repurchases have been implemented in Taiwan over many years, and therefore this paper explores whether stock repurchase will affect the result of dividend announcement. The goal of this paper is to investigate whether stock repurchase is a substitute of cash dividends. We find stock repurchase will strengthen the positive result of dividend increasing and reduce the negative impact of dividend decreasing. In addition, we find that the effect of stock repurchase on cash dividend announcement result is larger than that on stock dividend. Besides, information signaling, free cash flow, and firm size can explain the results of dividend announcement, especially in value stocks.