摘要： 交易定性在税法分析中占有举足轻重的地位。交易定性围绕认定纳税主体、税收客体的有无、定性和量化以及由此延伸的税收管辖权等税企争议的关键环节展开。在单一合约交易，法律关系与交易定性具有同一性，税法与私法呈协调与融合状态；在复合交易、“名—形”冲突或“名—实”冲突的虚假交易，合同性质与交易定性分道扬镳，税法与私法呈现冲突与龃龉。实务中，交易定性应从行为和所得主体的“名—实”冲突或“形—实”冲突、“法律关系”和“交易定性”的协调与冲突、税收客体的“定性”与“定量”的决定关系中来把握，凸显税收活动的法律属性、交易定性与法律关系的辩证关系和税法追求实质正义的精神气质。

关键词: 交易类型, 合同性质, 交易定性, 税法特质, 实质课税

Abstract: Transaction characterization plays an important role in tax law analysis. It is embodied in the concrete stepsto ascertain the taxpayer, tax object's existence, true nature and the quantization when the enterprise and tax authorities are in dispute. In a single contract transaction tax law and civil law are in harmony as the legal relationship is in line with the transaction characterization. In a composite transaction, the true nature of the contract isinconsistent so that tax law isn't in line with civil law. In tax law practice, transaction characterization shall bedefined in the coordination and conflict between “name and nature” or “form and substance” of behavior objectand income object, between the legal relationship and the tax transaction characterization, as well as in the prevailing relationship between deterring the nature and the quantization of the tax objects ．From that point of view,in China, the tax administration is of legal attribute, transaction characterization and true nature of contract are indialectical relationship, and it demonstrates that tax law is of the spirit of pursuing the substantial justice and of unique spiritual temperament.

Key words: Types of Transactions, Nature of Contract, Transaction Characterization, Peculiarity of Tax Law, Substantial Justice