ㆍ668 Called as Ingmae-hyeon in the 27th year of King Bojang of Coryo

ㆍ757 Called as Jeongseon-hyeon, Myeongju when the nation was divided into nine            provinces

ㆍ1012 Promoted to Jeongseon-gun from Jeongseon-hyeon

ㆍ1895 Changed to Jeongseon-gun, Chungju-bu from Jeongseon-gun, Gangneung-bu

ㆍ1896 Reverted to Jeongseon-gun when the nation implemented a 13 province system

ㆍ1906 Imgye-myeon and Doam-myeon, Gangneung-gun, and Sindong-myeon              Pyeongchang-gun were incorporated into Jeongseon-gun

ㆍ1924 Seo-myeon was incorporated into Jeongseon-myeon

ㆍ1931 Doam-myeon was incorporated into Pyeongchang-gun by ministerial ordinance              No.11(promulgated on Feb. 28, 1931)

ㆍ1935 Parts of Doam-dong and Baekil-dong in Jeongseon-myeon were incorporated into              Ganpyeong-ri, jinbu-myeon, Pyeongchang-gun

ㆍ1973 Jeongseon-myeon and Sabuk Branch Office of Hwaam-myeon were promoted to              eups(two eups and five myeons)

ㆍ1980 Sindong-myeon of Jeongseon-gun was promoted to Sindong-eup(three eups and              four myeons)

ㆍ1985 Sabuk-eup was divided into Gohan-eup and Sabuk-eup (four eups, four myeons              and two branch offices)

ㆍ1986 Bukpyeong branch office of Buk-myeon was promoted to Bukpyeong-myeon(four              eups, five myeons and one branch office)

ㆍ2006 Currently there are four eups, five myeons and one branch office