To clarify the place of production of the metal threads or strips embroidered on the original ethnic garments of the Ainu people, Ainu garments and brocade garments made during the Ming and Ching dynasties in China have been analyzed using X-ray spectrometry and X-ray diffractometry. From the comparison of the composition and external form of these metal strips we conclude that the metal threads used in the Ainu garments were imported from Japan (Honshu), but not from China, nor were they re-used from Chinese costumes. Gold, silver, copper, haematite, silica and clay minerals, such as kaolinite, were identified in the metal threads by X-ray diffractometry.