分期分級董事會制度在企業公司治理政策中是否為一正向的措施,在文獻中有許多不同面向的研究。本文利用股票價格建構三個企業股價暴跌風險之衡量指標作為應變數,並探討分期分級董事會制度對股價暴跌風險之影響。我們採用1999年至2018年美國上市公司的資料做為研究樣本,研究結果發現:分期分級董事會與股價暴跌風險之間呈現顯著負相關,此結果顯示此制度為一正向策略,能降低公司股價暴跌發生的可能性。此外,實證結果顯示,若公司的審計委員會規模較大或是機構投資人比例較高的話,在實施分期分級董事會制度的條件之下,更能降低公司股價暴跌的風險。同時,實證結果亦指出,若公司創立初期即實施分期分級董事會制度,股價暴跌的風險將能顯著的下降。;Whether the adoption of staggered board policy has a positive effect in corporate governance remains controversial in the literature. In this study we use the stock price to construct three measures of stock price crash risk as dependent variables, and examine the effect of the adoption of staggered board on stock price crash risk. We use the data of listed firms in the United States with the period from 1999 to 2018 as our sample. The results show that there is a negative correlation between the adoption of staggered board and the risk of stock price crash, which confirms that this policy is positive for companies to reduce the occurrence of stock price crash. In addition, we find that a company with a larger audit committee or a higher proportion of institutional investors also reduces the risk of a stock price crash under the condition of adopting staggered board policy. Furthermore, the empirical evidence reveals that when the company adopts staggered board policy at the early stage of its establishment, the risk of stock price crash can be effectively reduced.