Using non-financial A-share listed companies in China from 2003 to 2017，we examine the impact of controlling shareholders’pledge of stocks on stock market information efficiency.Our findings show that controlling shareholders’share pledging damages the stock market information efficiency.Specifically，compared to firms without controlling shareholder pledging their shares，firms with share pledging by the controlling shareholder are less likely to disclose firm-specific information and thus have a higher level of stock price synchronicity.Furthermore，the fostering effect of controlling shareholders’pledge of stocks on stock price synchronicity is more pronounced in firms using the pledge financing funds to support entities other than themselves and firms with lower information transparency，and the damage to stock market information efficiency is also greater.