This research is aimed to know why the tax knowledge gives negative effect to the level of tax compliance. The behavior of tax compliance may be seen by observing the understanding of the tax payers about the tax information which is manifested in the increase of tax payer compliances. The data collection is done by distributing questionnaire and the number of sample is 125 respondents. The result shows that the tax knowledge gives negative effect on the level of tax payer compliances. The significant level of the tax knowledge on the tax compliance is 0,927 dan β -0,010.