This study aims to determine the effect of understanding of taxation, self assessment system, tax rates, and justice on tax evasion in OPD Bantul Regency. The population of this research is the employees in OPD Bantul Regency who have NPWP. Samples taken were 108 respondents. The sampling technique uses purposive sampling method. The data analysis technique used is the multiple linear regression method and testing using SPSS 23. The results of this study indicate that understanding taxation and justice affects tax evasion. Meanwhile, the self assessment system and tax rates have no effect on tax evasion.