| 1947 |
東京都中央区京橋に会社設立 |
| 1947 |
横須賀、門司、大牟田、佐世保で輸入塩物流事業開始 |
| 1947 |
The company founded in Kyobashi, Chuo-ku, Tokyo. Salt import business started in Yokosuka, Moji, Omuta, and Sasebo. |
| 1950 |
中国、スペインその他各国から塩の輸入事業を開始 |
| 1950 |
Import of salt from Spain, China and others started. |
| 1952 |
東京都品川区、広島市で倉庫営業を開始 |
| 1952 |
Warehousing business started in Shinagawa, Tokyo and Hiroshima. |
| 1954 |
外塩輸入商社の登録を受ける |
| 1954 |
Officially certified as overseas salt import house. |
| 1961 |
日中友好商社の指定を受ける |
| 1961 |
Designated as a 'Japan-China Friendly Trading Company'. |
| 1966 |
メキシコ塩の輸入を開始 |
| 1966 |
Commenced import of Mexican salt. |
| 1967 |
北九州市小倉北区で倉庫営業を開始 |
| 1967 |
Warehousing business started in Kitakyushu City. Head Office relocated to Toranomon、Minato-ku, Tokyo. |
| 1970 |
東京都大田区平和島で倉庫営業を開始 |
| 1970 |
Warehousing business started in Heiwajima, Ota-ku, Tokyo. |
| 1976 |
東京都足立区入谷で倉庫営業を開始 |
| 1976 |
Warehousing business started in Iriya, Adachi-ku, Tokyo. |
| 1980 |
北京駐在員事務所を開設 |
| 1980 |
Representative office opened in Beijing. |
| 1982 |
上海駐在員事務所を開設 |
| 1982 |
Representative office opened in Shanghai. |
| 1986 |
東京都江戸川区葛西で倉庫営業を開始 |
| 1986 |
Warehousing business started in Kasai, Edogawa-ku, Tokyo. |
| 1997 |
中国現地法人共華貿易（上海）有限公司を設立 |
| 1997 |
Subsidiary 'Gonghua Trading' established in Shanghai. |
| 2008 |
ISO9001認証取得 |
| 2008 |
ISO 9001 certified. |
| 2012 |
共栄商事天王洲ビル竣工、ビル賃貸事業を開始 |
| 2012 |
Building lease business started. Head Office relocated to Yurakucho, Chiyoda-ku, Tokyo 65th anniversary of the company. |
| 2024 |
北九州 塩加工設備全面リニューアル |
| 2024 |
Kitakyushu salt processing facilities fully renovated. |
| 2025 |
北九州 物流倉庫リニューアル |
| 2025 |
Kitakyushu logistics warehouse renovated. |
