Dotaku is a bell-like bronze object made in the Yayoi period (ca. 3rd century B.C.-ca. 3rd century A.D.) and characteristic of Japan. Lead isotope ratios of 53 dotaku owned by the Tokyo National Museum were determined. They were classified into three groups, alpha, Ê3 and gamma. Type alpha, in which two dotaku of the oldest style belong, shows the ratios ₂₀₇Pb/ ₂₀₆ Pb 0.8223 and 0. 8430-0.8434, which value is similar to Korean bronze objects. Type Ê3, represented by 33 dotaku of the middle-period style, has the ratio ca. 0.870-0.890, which is similar to the ratio of the Former Han mirrors. Type gamma (18 dotaku) shows the ratio 0.8763 ± 0. 0008, indicating the same raw material as those originating in China. The relationship between the style of the dotaku and their lead isotope ratios as well as raw materials are discussed. See 18-698 and 19-696. -- AATA