The “V得~” and “V不~” are two kinds of different developing structures in Qi Min Yao Shu. These two structures are interrelated and mutual to each other. Syntactically, both of them are from the Serial Verb Construction, from Ancient Chinese, and all are Grammaticalizing, but the point and the degree of the grammaticalization are different. The “de” in the “V得~” depends on a verb and gradually grammaticalizes. In this process, the most used case of “de” is used as possibility in Qi Min Yao Shu. It can provide some syntactical basics for the definite formula of Potential Complement, but the syntactical collocation of “de” and the content after it, is still not perfect. The content after “bu” in the “V不~” structure gradually grammaticalizes too. “bu” and “V” make a relatively stable syntactical position for the “bu”. But the fact that other contents can also enter this position, shows that “V不C” structure is still not stable. Semantically, both of the structures have an “action-result” meaning relationship. “de” and “bu” all can both direct the whole of the event-“V+~”. Additionally, all can express the possibility of the event and provide some semantical conditions for the formation of the Potential Complement. But the semantical feature of the result meaning, which was directed by the “de”, is still not perfect. In the meantime, the “bu” in the “V不~” can be used in unknown contexts to show a possibile meaning, and can also be used in known contexts to show a result meaning which is expected. It shows the meaning relationships of both structures that are not perfect. Pragmatically, all of them have the same pragmatical structure “structure center - expression core”, which is suit for the pragmatical requirement of the Potential Complement. But the function of the pragmatics is not perfect because of the developing syntactical conditions and semantical conditions.