Abstract:Theories on legal structure of alienation guaranty are divided into ownership theory, guaranty theory and the theory in the between. This paper focuses on the demonstrative principle of real right and divides the parties' right into legal right and real right. The legal right can be evidenced by third party to against the real right if it has been demonstrated and the third party knows or should know its existence. But the legal right can not be evidenced to against the real right between two parties.