This study aims to analyze that affect to perception on non ethical of tax evasion. These factors are fairness, tax system, discriminant, and probability of fraud detection. The populatio of this study is the individula tax payer in KPP Pratama Bantul and Sleman. The sampling technique of this study used convenience sampling method, where the data obtained from questionnares with 88 respondenses. data anlysis in this study assised by SPSS software. The result of this study are follows: (1) fairness on perception of non-ethical tax evasion is positive and significant, (2) tax system on perception on non-ethical tax evasion is positive and significant, (3) discriminant on perception of non-ethical tax evasion is negative and significant, (4) probability of fraud detection on perception of non-ethical tax evasion is positive and significant.