以国家契约论为基础,可以推导出税收法律关系在本质上是一种公法上的债务关系,其既有一般金钱之债的双方当事人地位平等又有一方具有优势地位的特征。情事变更制度作为债法中的制度是适用于具有平等性特征的税法的,把它引入税法的价值在于赋予纳税人税收减免请求权以维护纳税人的税收权益。 Based on the state contract theory, it can be deduced that the legal relationship of taxation is essentially a kind of public-legal debt relationship. Both parties have the equal status of money and one has the dominant position. The system of changing the affair as the system of debt law is applicable to the tax law with equal characteristics. The value of introducing it into the tax law lies in giving the taxpayer the right to demand tax relief to safeguard the tax rights and interests of taxpayers.