The conclusion of this paper is as follows. : We think that it was planned that after a whole scale is first assumed in Long Duc Dien, the edge pillars interval is set as a basic dimension, and the pillars interval was decided by the ratio of the pillars interval or the integral multiples of a unit length. Secondly, we think that the diameter of “mokoshi” pillar is set as a unit length, and the relation of the ratio of the pillars interval and the difference of the pillars interval exists between the each pillars interval when the pillars interval is decided according to a unit length. Thirdly, we think that the section size of Long Duc Dien was decided depending on the proportion coefficient (1/2, 1, √2, 5/3, 2) being multiplied to the pillars interval.
