The purpose of this study is to investigate the effect of Covid-19 on the audit quality of companies listed on the stock exchange. The present study is an applied research in terms of purpose-based classification. The purpose of applied research is to develop applied knowledge in a specific field. The statistical population of the present study includes the auditors of the auditing organization and the Society of Certified Public Accountants of Iran (who are auditors of listed companies). The sampling tool is a standard questionnaire that after performing face validity with the help of respected faculty members, its construct validity was confirmed by Smart PLS software. Reliability was calculated and confirmed using Cornbach's alpha. A structural model was used to investigate the relationship between research variables. Also, in terms of inference about research hypotheses, it is in the descriptive-correlational research group and Smart-pls structural equation modeling has been used to test the hypotheses. Findings show that the relationship between Covid-19 on the audit quality of companies listed on the Tehran Stock Exchange has been significant and it can be said that in times of crisis caused by the Corona virus, not only the application of accounting and auditing standards requirements than before It is not reduced, but their full and accurate use and maintaining and improving the quality of reporting is more emphasized.