Renamed as Jeongsyeon-hyun in the 16th year of King Gyeongdeok, Silla and became a district directly controlledby the lord of Myeongju Province
1018
Elevated from a district to a county in the 8th year of King Hyeon-jong, Goryeo
1291
Renamed as Dowon in the 17th year of King Chungyeol, Goyreo
1310
Renamed as Dowon in the 2nd year of King Chungseon, Goryeo
1353
Recovered as Jeongseon in the 2nd year of King Gongmin, Goryeo
May 26, 1895
Changed its administrative affiliation from Gangneung Province to Chungju Province (Decree No. 101, May 26, 1895)
Aug. 4, 1896
Returned to Gangwon Province with a 13 Provincial System (Decree No. 30, August 4, 1896)
Oct. 1st, 1906
Imgye-myeon and Doam-myeon were transferred from Gangneung-gun and Sindong-myeon was transferred from Pyeongchang-gun (8 myeons)
Apr. 1st, 1931
Doam-myeon was incorporated into Pyeongchang-gun (Ministerial ordinance No. 11 February 28, 1931) (6 myeons)
Dec. 25, 1935
Parts of Doam-dong and Baekil-dong in Jeongseon-myeon were transferred to Ganpyeong-ri, Jinbu-myeon, Pyeongchang-gun while parts of Cheonpo-ri and Seokhang-ri in Sindong-myeon were transferred to Yeonsang-ri, Sangdong-myeon, Yeongwol-gun (6 myeons)