Korea did not begin to use money until the Koryo Period (Goryeo 高 麗) (936-1392 AD) when coins from China's Song Dynasty (宋朝) (960-1279 AD) were imported and began to circulate. Prior to this time, barter based on rice and cloth was the principal means of exchange.
The first coins actually minted in Korea occurred during the 15th year (996 AD) of the reign of King Songjong (成宗). This coin was cast in both bronze and iron and was based on the standard Chinese cash coin which was round with a square hole in the center.