Fen(分°) is the proportional dimension unit of the standard timber section on Yingzaofashi(營造法式), and there is a phrase that not only structural members but the whole structural design of a building also use Fen as the dimension unit on the book. But in fact only the section dimensions of structural members are recorded by Fen, but the design dimensions are recorded by Chi(尺) on the book. Other historical records also described the building size by Chi. So there has been long-standing debate on the phase in Chinese architectural history society, including the recent confrontation on the analysis of survey figures of the east great hall of Foguangsi temple(佛光寺東大殿). This paper analyzes all the records about the size of structural members and section planning on the book to make various calculation and evaluation. And it makes a survey of Cai(材) as the dimension and design unit between Chi and Fen through geometric analysis. Cai might be a rough unit of measurement in terms of structural and proportional scheming on Yingzaofashi, and the full size Cai(足材) had been a building scheming module before the Song dynasty.

This paper aimed at analyzing of structural carpentry terminology for bracket structure in Yingzaofashi《營造法式》in the era of Song Dynasty and illuminating coinage characteristics and method of Structural Carpentry Terminology for bracket Structure through graphonomy research and system and structure of these terms. The results are as follow. The structural carpentry terminologies for structure were identified to be approximately 23 words, and terminology of bracket structure鋪作is largely categorized into 3 categories of Type鋪作次序, Structure, Place. On the other hand, the structural carpentry terminologies for parts largely categorized into 2 categories of Bracket structure鋪作, Others. Bracket structure terminologies for parts were derived from the core of Dou枓, Gong栱, Ang昂, Fang方. The phenomena of derivation in structural carpentry terminology for bracket structure can be explained by the difference in the shape of subsidiary material and the location for usage of the subsidiary material and part of the subsidiary material and their functions.

In ancient times, architectural design was seen as a critical task in building technologies. Specifically, form, dimension and structural design are of significant. These aspects are associated with each other and to be emerged as a whole. Designing plan dimension was deemed to be the core of design technology due to its close relationship with module system. Thus, its evolution as well as development process typically represents and reflects the spirits and contents of design technologies in ancient China. In China, the materials regarding ancient architectural technology include Yingzaofashi(營造法式) of Song Dynasty and Gongchengzuofazeli(工程做法則例) of Qing Dynasty. They show many aspects concerning materials, structure, scale system and building. In Yingzaofashi, although the length of objects are decided by 'cai(材)' and 'fen(分)', there are no regulations on length, width and height of a building. However, in the construction of ancient buildings, the above mentioned basic scales are very important in both design and construction. The present paper attempts to discuss the significance, namely, the design principles of length, with and height of ancient chinese architecture.