中文摘要：

本文研究独立董事辞职行为对外部投资者而言是否具有信息含量。研究结果发现：（1）在短时窗内，投资者对非规定性独立董事辞职（即不是因为届满或按照监管规定而必须的辞职）公告的反应消极；（2）在独立董事非规定性辞职发生后250个交易日内的长时窗，公司的平均累计超额收益率显著为负值；（3）在那些没有对独立董事表示感谢的公司公告中，上述效应更为明显。这意味着投资者可以通过观察独立董事辞职行为及相关信息进行投资决策。

英文摘要：

The study examines the information content of independent director resignations in China. The paper firstly uses event study and finds that investors react negatively around the event date to non-compulsory resignations of independent directors, who resign not because of the tenure or governmental regulations. Then the author analyzes firm performance after independent director resignations and fined that the average CARs over a 2.50-day post-resignation period are significantly negative. The negative value effects are more significant in those firms whose resignation announcements did not deliver the thanks to the resigned independent director. The results confirm that investors can make their investment decision according to the information content of independent director resignations.