税收债权债务关系的主体包括两类:一是税收债权人,一是税收债务人。税种法的规定仅确定具体税收债权债务关系发生的依据,至于何种人需具备何种条件方可成为税收债务人,税法并无明确的规定,学术界的看法也不尽相同。借鉴私法主体资格的构成要件,税收债务人的主体资格构成要件应该包括税收权利能力、税收行为能力和税收责任能力三方面,据以明确纳税人的负税能力。 The main body of tax credit and debt includes two types: one is the tax creditor and the other is the tax debtor. The tax code only determines the basis for the occurrence of specific tax, credit and debt relations. As for what types of people need to be tax debtors, the tax law has no clear rules and the views of academics are not the same. Drawing on the constitutional requirements of the main body of private law, the constitutional requirements of the tax debtor’s main qualifications should include the tax rights, tax capacity and tax liability capabilities, so as to clarify the taxpayers’ negative tax capabilities.