Abstract: Compared with the preceding dynasties,in Song Dynasty, the content in the system of levying the business tax were rather abundant.The official expression on levying business tax shows that the taxation levied by the state was just less than half of the businessmen's income and business tax did not affect the normal circulation of commodities.And the government attempted to carry out the levy and the supervision legally.However,in practice of levying business tax,the levy violated the law and increased the b...