The aim of the article is to identify the factors determining the taxpayer’s behavior, to evaluate Lithuanian taxpayer’s behavior by changing tax policy of VAT. The article investigates whether the increase of VAT burden in Lithuania has a significant impact on taxpayer’s behavior, encouraging them to voluntarily pay taxes or avoid tax liabilities. The research period is from Q1 2000 - Q4 2016. The study uses VAT gap data. Research methods: correlation analysis, vector auto regression (VAR) model. The use of correlation analysis allows to establish the relationship between tax rates and changes in taxpayer’s behavior, while the vector auto regressive method allows to investigate taxpayer’s behavioral responses to the changes of tax rate. According to the responses of the impulse functions, the response of taxpayer’s behavior (tax avoidance) to the changes in tax policy is determined. The investigation showed, that in the short term, the increased tax burden may lead to decrease of VAT gap, in the medium term an increase in tax burden on VAT may increase the level of tax avoidance in the country.