The classical literature states that earnings management contains opportunistic incentives as well as non opportunistic incentives. However, there is little research shedding light on the non opportunistic earnings management in China. We exploit the institutional background that “A+H” share companies listed in both the Mainland and Hong Kong firstly discloses key audit matters in 2017, and adopt Difference in Difference (DID)together with Propensity Score Matching (PSM) methods to test the impact of key audit matters disclosure on earnings management incentives. The research finds that the disclosure of key audit matters improves the correlation between real earnings management and future earnings, indicating that the disclosure of key audit matters constrains the opportunistic incentives of real earnings management and strengthens its non opportunistic incentives. Further analyses show that this effect mainly exists in the companies with low audit quality, weak internal control. Additionally, this effect is more pronounced when the descriptive paragraph involves impairment and allowance for receivables, the solution paragraph involves the usage of the work of valuation expert to deal with key audit matters, or a firm’s level of net operating assets is low. These results indicate that the disclosure of key audit matters may enhance the non opportunistic incentives of real earnings management by improving audit quality and internal control level and limiting accrual earnings management.