In Japan the use of bronze artifacts began in the Mid-Yayoi period (1st century A.D.) or more than 1,000 years later than in China. After describing in detail the method of sampling and the analytical methods used, the author lists the results of analysis of 95 objects including mirrors, dotaku, arrow heads, swords, and personal ornaments in two tables; the first tabulation is for main constituents, Cu, Sn, Pb, done by wet analysis; the other tabulation covers trace elements, As, Sb, Bi, Au, Fe, Ni, Co, and Zn estimated spectrochemically. Period and provenience are indicated. Twenty of the objects analyzed are illustrated and 24 metallographs reproduced. Bronze mirrors of the Yayoi period contain in general about 25% Sn and 5% Pb and were probably made in China. Mirrors of the Tumuli period, which contain less Sn and Pb, were probably made in Japan. Dotaku (bell shaped objects) of the Yayoi period, which are mainly Japanese in origin, generally range 5 to 10% Sn and about 5% Pb. Swords and spear heads run 15-20% Sn with widely varying amounts of Pb. Arrow points of the Tumuli period average about 20% Sn and about 5% Pb. In the great majority of the objects analyzed zinc is absent or present only in minor or trace amounts. In general in more recent periods the proportion of Sn in the alloys becomes smaller. It is conjectured that this in part may have resulted from the practice of remelting old objects or scrap to make new ones with resulting Sn lower content. Also, after the advent of iron, bronze objects including arrowheads were made more for ceremonial than for utilitarian purposes; hence it was an advantage to lower Sn content for economic reasons. -- AATA