The Ondol has been considered as a unique artifact of traditional heating system in Korea. It was originated in northeastern area of China, however, very few of korean researches paid attention to the development of Ondol in this area, specially after Balhae period. Since 1980, Chinese archeologist have excavated some relics which are significant to review the development of Ondol. This study aims at finding the characteristics of Ondol during Liao-Jin period in northeastern area of China. Through the excavation reports, 20 relics of Ondol construct during Liao-Jin period were found. By analyzing these data, the result of this study is concluded as followings; The type of Ondol in Lio period was ㄱ shape with 2-3 tunnels which seems to be succeeded to the Balhae type. During Jin period a new type of ㄷ shape with 3-4 tunnels created by Nuzhen which is rarely discovered in korean peninsula. This type was the original type succeeded to the Ching period and nowaday in northeast area of China. That means different direction of Ondol development in Korean peninsula and in northeastern China.