The fiscal and taxation system reform represented by replacing the BT with a VAT is the breakthrough of the current supply-side structural reform. By adjusting the tax base to optimize the structure of enterprise expenditures,enterprises are encouraged to increase their R & D investment so as to reduce their tax burden and improve the competitiveness of enterprises. Taking the Chinese listed firms between 2009-2016 as samples, the annual data of wind database and CSMAR database,we adopted DID model to inves...