Popuse: Financial information plays a vital role for stakeholders in the capital market and the quality of this information is of great importance. Therefore, the purpose of this study is to investigate the effect of the firm's debt structure on the relationship between auditors' grade change and information asymmetry.

Method: In order to achieve the objectives of the research, a sample consisting of 131 companies accepted in the Tehran Stock Exchange was selected using systematic elimination sampling during the years 2014-2023, and finally the research hypotheses were selected with the help of multiple linear regression test. It was done based on panel data.

Findings: It was observed that there is an inverse and significant relationship between auditors' grade change and information asymmetry. Also, the interaction between auditors' grade change and the firm's debt structure affects this relationship.

Conclusion: In order to reduce information asymmetry and maintain proprietary interests and respect the rights of stakeholders, company owners can reduce the amount of influence and manipulation of managers in financial reporting by using well-known auditors with higher ranks and ranks, and ultimately information asymmetry will be reduced. The company's debt structure is also effective in this regard because when the company uses a lot of long-term debt in its financial structure Certainly, managers try to manipulate information a little bit to protect their image and the company, which will ultimately increase information asymmetry.