The present research aims to investigate the effect of tax ethics, mental accounting and self-tax knowledge of employers on their tax compliance (a case study of real taxpayers of Yazd province) in the period of 1401 to 1402. In terms of its nature and method, the research is a descriptive-survey type of research, and it is considered practical in terms of its purpose. The statistical population consists of real taxpayers of Yazd city and the statistical sample was made through the Cochran formula and available sampling method, and finally 384 people were selected as the sample size. The tool of data collection was a questionnaire, which was used to measure tax compliance by Guzel et al. (2019), to measure tax ethics by Palil (2010) questionnaire, to measure tax knowledge by Haj Mohammadi questionnaire (2013) and to measure mental accounting by Radinto questionnaire. (2020) was used. The content-form validity and construct validity (confirmatory factor analysis, convergent and divergent validity) of the research tool were examined and confirmed, and its reliability was also measured using Cronbach's alpha coefficient test and composite reliability, and considering that the alpha value for all The research variables were obtained more than 0.7, the reliability of the research tool can be confirmed with confidence. In order to analyze the data, descriptive and inferential statistics methods have been used, in the first part, frequency tables and graphs, and in the second part, the partial least squares method, by means of SPSS and SmartPLS software, have been used to test the hypotheses and present the research results. Is. The results of this research showed that tax knowledge, mental accounting and tax ethics have a positive and significant effect on the tax compliance of real taxpayers. In addition, tax knowledge had a positive and significant effect on mental accounting, but mental accounting could not moderate the relationship between tax knowledge and tax compliance, and no difference was observed in the use of mental accounting between self-employed men and women.