”Lü Convention” is recognized as the originator of the later convention. The current researches of ”Lü Convention” are mainly in the view of social history or legal history. As to the ideological history background of ”Lü Convention”, especially its Guan School characteristics, as well as Zhang Zai and Lü Dajün's personality on its naissance, have not gotten full attention. Only through a thorough understanding of the Guan School's ”in comparison with Buddhism, who is better”, ”Li is the first in Zhang Zai's teaching” and its metaphysical theory basis, can we deeply understand ”Lü Convention”'s naissance background and its great historical significance.