Using the 2017 audit report of Chinese A-Share listed companies， we analyze the characteristics of the first full disclosure of critical audit matters. We find that accounts such as “income” and “receivables” are the most concerned accounts in the critical audit matters. “Revenue recognition” and “asset impairment” are the two most important issues in the critical audit matters of A-share listed companies. The empirical test reveals that the disclosure of critical audit matters reduces the timeliness of the 2017 audit report， increases audit fees， and at the same time， improves audit quality. Further tests reveal that the improvement in audit quality is mainly from “non big-ten” subsamples and higher market index subsamples. This study shows that although the disclosure of critical audit matters takes some time of audit firms， it leads to higher audit quality.