Abstract: Withthe subsidy scope increasingly expanded and the subsidy amount increasingly high, the policy of the patent fees funded by government is widespread implementedin China and is increasingly questioned in academic circles. The effect mechanism of the patent fees upon social welfare is analyzed through a simple game model, and it is found that the patent fees subsidy policy implementedby government can indirectly reduce the level of social welfare by directly affecting the patent application behavior of innovators. On this basis, it is suggested that the government should raise the patent fees standard and clarify the subsidy priority of patent fees.