Jar coffin refers to a potteries used as a coffin or reliquary container in the prehistoric period. The total of 15 jar coffins were examined at the Samhwa archaeological site in jeju. Except for the one which only a single inverted jar was used, most are used that two jars placed horizontally as the use of coffin. Two jars using coffin display the characteristic features of the Samyangdong Style Pottery with only slightly flaring lips.
Unearthed jars, up to now, were Gwankijiri Style jars, which are marked by the mouth part significantly outflared. Meanwhile, Jar coffin in the Samhwa prehistoric site is regarded as the earliest of all the prehistoric site in Jeju so far.