Findings from a survey of architectural members and iron tools excavated from the ruins of the Yayoi and Kofun periods are summarized as follows : (1) Among major architectural wooden materials in Japan，the most often used in the Yayoi and Kofun periods were Japanese cedars，Japanese cypresses，and chestnut trees， (2) Appropriate types of wood were selected for the various elements of wooden buildings，based on the particular characteristics of each species chosen. (3) An element of technology that seems to have been handed down from the Jomon period to the Yayoi and Kofun periods seems to be the processing methods for the joints of architectural members (4) The categorization of tools in the Jomon period is thought to be handed down to the categorization of tools used in the various stages of logging， lumbering， and the processing of architectural members during the Yayoi and Kofun periods. (5) As far as iron axes and adzes are concerned，it appears that iron axe blades were classified into axes for felling and adzes in the Yayoi period and were classified into axes for felling，axes for rough hewing，and adzes in the Kofun period according to respective functions. (6) 1ron chisels in the Yayoi and Kofun periods are thought to have been classified into large chisels using axe blades and chisels for rough processing or finishing according to respective functions. (7) The categorization of major architectural tools in the Yayoi and Kofun periods seems to consist of iron axes，adzes，and chisels.

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Historically，Japanese carpenters' tools are said to be significantly influenced by those of China and　Choseon Bando， Following our findings from a survey of Chinese carpenters' tools and based on　acquired documents，a comparison study was made with Japanese squares， 1) Archeological specimens indicate that metal squares with graduations，referred to Kara–shojaku，existed in China，However，modern Chinese squares are made of wood (or bamboo) and often have　graduations on only one side， Regarding their shape，some are simply L–shaped. while others have a　diagonal section attached to an L–shaped section， 2) Japanese squares are thought to have been made of metal since the Nara period. and all　Japanese squares are now made of metal. In the Edo period.th ese were made of iron or brass， In the final days of the Edo period，graduations were present on two sides， Graduations began to be added to the back side and were referred to as Urame，and characters designating good or ill fortune also began to be used， However. graduations do not seem to have been standardized in the early Edo period，The existence of Urame is confirmed by actual specimens (excavated in Sakai) and documents (Jirinkoki) in the early Edo period， As far as Urame are concerned，Chinese squares that were used to measure angles of 45 degrees could easily obtain an inscribed square in a circle， Because there are no specimens or documentation supporting the existence of rulers measuring 45 degrees in Japan before the Edo period，it is possible that the back side of rulers measuring 45 degrees was used for conversion to Urame earlier in history in Japan， 3) A ruler marked with characters designating good or il fortune is called a Feng Shui Ruler (Rohan– jaku) in China， According to certain documents (Jirinkoki)，a ruler of 1.2 shaku for construction was first divided into eight sections， In the Ming dynasty， rulers of 1.44 shaku began to be divided into eight sections， Various Monjaku thought to equal to 1.44 shaku were discovered in the course of archaeological field work. As squares of 1.2 shaku were divided into eight sections in Japan in order to mark characters designating good or ill fortune，these Monjaku appear to have developed during the Southern Song dynasty，

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