This study examines the effect of Perceived Usefulness, Perceived Ease, Security and Privacy, and Individual Taxpayer Satisfaction towards the Behavior of using E-filing. The population is all individual taxpayers registered in KPP Pratama Purbalingga. Sampling method used is accidental sampling and obtained sample of 100 respondents. This study used multiple linear regression to test hypothesis.The results of the analysis showed that Perceived Usefulness positively affect the Behavior of Using E-filing, while Perceived Ease, Security and Privacy, and the Taxpayer Satisfaction has no positive effect on the behavior of using E-filing.