Abstract: The final judgment sale contract is against the principle about the subjective scope of res judicata effect. It is not allowed that the subject beyond the principle becomes qualified in the procedure of execution and application for court enforcement in his own name. Such an attempt at boundless expansion of subjective scope of res judicata is forbidden by law. The judgement sale contract is different from litigation and litigation trust. Neither can it be classified as litigation take-on system, nor litigation trust system. What's more, the litigation trust is also forbidden by law. The enforcement right of claim, the object of judgment sale contract does not have the characteristics of strong liquidity, artificial divisibility, nominal value invariance like the financial assets. So it does not belong to the financial asset transfer contract. The subject of debt certificate transfer contract is legitimate for it has the features of liquidity and property instead of the factor of person and public law. So the debt certificate transfer contract shall be legal and effective.