||Named Siljikguk or Siljikgokguk (Mahan Territory)
|Period of the Three States (Before Century)18C ~ 668
||Annexed to Silla (in the 23rd year of the reign of King Pasa)
||Annexed to Goguryeo (in the 56th year of the reign of King Jangsoo)
||Renamed Siljikju (Isabu, in the 6th year of the reign of King Jijeung of Silla Dynasty)
||Renamed Bukjin (in the 5th year of the reign of King Muyeul of Silla Dynasty)
|Unified Silla 668 ~ 935
||Renamed Samcheok County (in the 16th year of the reign of King Gyeongdeok)
|Goryeo918 ~ 1392
||Renamed Cheokju (in the 14th year of the reign of King Seongjong)
||Renamed Samcheok Prefecture (in the 9th year of the reign of King Hyeonjong)
|Joseon1392 ~ 1910
||Upgraded to Samcheok bu (in the 2nd year of the reign King Taejo)
||Renamed Samcheok Protectorate (in the 13th year of the reign of King Taejong)
||Name changed from Samcheok Protectorate to Samcheok County (in the 32nd year of the reign of King Gojong)
|Japanese Colonial Period 1910 ~ 1945
||Bunae and Malgok-myeons among 12 myeons (sub-counties) were integrated into Bunae-myeon, and Dosang, Doha, and Gyeonbak-myeons were renamed Buksam-myeon.
||Bunae-myeon was upgraded to Samcheok-myeon.
||Samcheok-myeon was upgraded to Samcheok-eup.
|Republic of Korea1945 ~
||Boksam-myeon was upgraded to Bukpyeong-eup.
||Sangjang-myeon was upgraded to Jangseong-eup.
||Sodal-myeon was upgraded to Dogye-eup.
||Hwangji branch district, Jangseong-eup, was upgraded to Hwangji-eup, thereby becoming the largest county nationwide with population of 300,000 people, 5 eups, and 5 myeons.
|1980. 4. 1
||Bukpyeong-eup was integrated into Donghae City in accordance with Law No. 3188.
||Wondeok-myeon was upgraded to Wondeok-eup by Presidential Decree No. 10050.
|1981. 7. 1
||Jangseong-eup and Hwangji-eup were upgraded to Taebaek City in accordance with Law No. 3425.
|1986. 1. 1
||Samcheok-eup was upgraded to Samcheok City with 6 subdistricts (Namyang-dong, Wolgye-dong, Gyo-dong, Jeongra-dong, Sajik-dong, Dowon-dong) in accordance with Law No. 3798.
|1986. 3. 27
||Ojeo branch district, Wondeok-eup, was upgraded to Gagok-myeon by Presidential Decree No. 11874.
|1989. 1. 1
||Yonghwa-ri and Jangho-ri in Wondeok-eup were integrated into Geundeok-myeon by Presidential Decree No. 12007.
|1989. 4. 1
||The Singi branch district of Dogye-eup, 7 ri administrative units and Machari districts were upgraded to Singi-myeon in accordance with Samcheok County Ordinance No. 1371.
||Wolgye-dong was renamed Dangjeo-dong.
||5 ri administrative units of Hajang-myeon were integrated into Taebaek City.
|1995. 1. 1
||Samcheok City and Samcheok County were integrated into Samcheok City in accordance with Law No. 4774.
||Sajik-dong and Dowon-dong were removed in accordance with Samcheok City Ordinance Nos. 270 and 271, and Dangjeo-dong was renamed to Seongnae-dong.