Since the study of C. Sachs was published, much has been written on the origin and process of distribution of Jew's harp in Eurasia. But no one has ever consulted the Chinese sources relating to it. I think the Chinese document is indispensable for the study of this problem. Here in this paper discussion is made on the Jew's harp with the help of Chinese historical records. Jew's harp is a musical instrument of percussion, consisting of an elastic steel tongue fixed at one end to a lyre-shaped frame, and bent at other end at right angle. It is played by holding the frame between the teeth and striking the free end of the tongue with the finger of player. The pitch is controlled by altering the size and shape of oral cavity. The name of this instrument appears in the texts of 16th century in Europe as Jew's harp. Attempts have been made to derive jew from jaw, but there is no apparent reason for connecting the instrument with jaw. Japanese people in Edo-period called this kind of instrument Biyabon or Biwa-bue (the flute with lute-like sound). And also this instrument has been known for centuries in China under the name of K'ou ch'in (口琴). The earliest mention of the use of this kind of instrument occurs in the " Lo-hsu (楽書)" written by Chen Yang (陳暘) who lived in 12th cnntury. Chen Yang was a government officer of Sung (宋) Dynasty, and a historian of music. His detailed biography is found in the "Sungshih (宋史)" of Chinese Annals of Sung Dynasty, vol. 432. In his book it is recorded that "leaf-shaped beating made of iron is used by people ; place the instrument at opening of mouth, a musical note is sounded and controlled by oral cavity (vol. 135)". This brief information shows that the musical instrument like K'ou ch'in was in the employ of the Chinese people in 12th century. The use of the instrument in China began at least four centuries earlier than in Europe. I do believe that the European Jew's harp has its origin in China. The same kind of instrument as K'ou ch'in has been widely distributed in the parts of the world, that is Tibet, Mongol, Indonesia, Indo-china, Melanesia, Siberia and other northern countries. I think that they might have been originated in China.