Using the hand-collected text data of the new-style audit reports of 5806 A-share listed companies from 2017 to 2018,we find that the companies stock liquidity improves with the increase of the disclosure level of key audit matters(KAMs)in the audit report which is measured by three methods including the matters，amount,the words of the KAM paragraph and the file size.The conclusions are still valid after considering endogeneity and doing a lot of robust tests.Further analyses suggest that there is a significant positive correlation between them only in the companies with lower internal control quality,smaller proportion of share holding of the large shareholder.The contributions of this research are that it proves the informational value of the disclosure of KAMs from the perspective of stock liquidity, and investigates KAMs，disclosure from the independent auditor,so extends the extant research field on the influencing factors of stock liquidity. Our conclusions show that the reform of the audit report achieves the expected purpose,and helps increase the efficiency of the security market.