【摘要】The tax burden differences of regions are very significant in China.The previous research literatures focus on theoretical speculations of causes,there is a lack of empirical evidence.This paper focus on the analysis relations between the tax base and tax burden,determine it is whether or not fair and reasonable that the impact of the tax system on various tax base,ultimately search system reason.Through research,this article has not significant evidences to support ownership structure,trade structure and regional differences(dummy variable)caused significant impact on the tax burden.Found that urbanizarion degree and the third industry's share of GDP are positive correlation with the tax burden.While GDP per capita and the proportion of workers compensation to GDP are negative correlation with tax burden.This is the most critical factor.It can be summarized as a system reason of indirect taxation as the main body.