1929	Establishment of Hanshin Harbor Construction Co., Ltd. with joint-funding by the South Manchuria Railway and Yamashita Kisen (Yamashita Steamship) Co., Ltd. for the purpose of reclaiming a site fronting on Naruo, Nishinomiya City, Hyogo Pref. and constructing an industrial harbor. President: Kamesaburo Yamashita, Head Office: Sakaemachi-dori, Kobe
1932	Start of business as construction contractor in addition to Naruo Reclamation Project.
1935	Head Office relocated to Fushimicho, Higashi-ku, Osaka.
1938	Naruo Reclamation Project interrupted due to war.
1945	Head Office relocated to Kawaguchimachi, Nishi-ku, Osaka.
1946	Received order for Tonegawa River dredging project (Chiba Pref.) as first project after war.
1952	Head Office relocated to Fushimicho, Higashi-ku, Osaka.
1960	Tokyo Sales Office upgraded to Tokyo Branch.
1961	Head Office relocated to Kouraibashi, Higashi-ku, Osaka. Listed in Second Section of Osaka Stock Exchange.
1962	Listed in Second Section of Tokyo Stock Exchange.
1964	Decision to resume Naruo reclamation project. Trade name changed to Toyo Construction Co., Ltd. Listed in First Sections of Tokyo and Osaka Stock Exchanges.
1965	Fukuoka Sales Office and Nagoya Sales Office upgraded to branches.
1967	Naruo reclamation ground-breaking ceremony.
1968	Tokyo Headquarters established. Okayama, Takamatsu, and Kanazawa Sales Offices upgraded to branches.
1969	Tohoku Branch opened.
1970	Absorption merger of Hitachi Zosen Coastal Construction Co., Ltd.
1971	Hokkaido Branch opened.
1972	Singapore Sales Office opened (start of advance into overseas markets).
1973	Overseas Business Dept. established (now International Branch). Received order for Navotas Fishing Port Construction Project (Philippines). Manila Sales Office (Philippines) opened.
1976	Architectural Construction Dept. and Sales Dept. established (advanced into construction field). Joint venture company CCT established in Philippines. Name of Tokyo Headquarters changed to Tokyo Head Office.
1977	Start of general sales of plots in Naruohama Industrial Center.
1983	Narawa Materials Center opened.
1984	Naruo Engineering Center opened (now Naruo Research Center).
1986	Sales of Naruohama Industrial Center completed. Received order for Kansai International Airport Island seawall construction (Osaka Pref.)
1990	Tomac Co., Ltd. established (company specializing in offshore construction).
1992	Received order for Changi Airport Reclamation Project (Singapore). Miho Research Center established.
1995	Occupied in Great Hanshin Earthquake recovery.
1997	Phnom Penh Sales Office (Cambodia) opened (now Phnom Penh Branch).
1999	Received company-wide ISO9001 certification. Received order for Kansai International Airport Phase II construction (Osaka Pref.).
2000	Received order for Chubu Centrair International Airport seawall, etc. construction (Aichi Pref.).
2001	Received company-wide ISO14001 certification.
2002	Announcement of business cooperation with Maeda Corporation.
2003	Announcement of Toyo Value-Up Plan (strengthening of cooperation with Maeda Corp., capital increase, etc.)
2004	Hanoi Sales Office (Vietnam) opened.
2005	Received order for Tokyo International Airport (Haneda Airport) Runway D construction (Tokyo).
2006	Jakarta Sales Office (Indonesia) opened.
2007	International Division upgraded to International Branch. Head Office relocated from Kandanishikicho, Chiyoda-ku, Tokyo to Omi, Koto-ku, Tokyo.
2011	Occupied in Great Tohoku Earthquake recovery.
2012	Reverse stock split executed (5 shares to 1 share). Received order for Mombasa Port Container Terminal construction (Kenya).
2013	Received order for Nghi Son Refinery plant (Vietnam) offshore work.
2014	Yangon Branch Office (Myanmar) opened.
2015	Kanto Architectural Construction Branch opened. Implementation of capital increase through a public offering and third-party allocation of shares
2016	Completion of self-propelled multi-purpose ship “AUGUST EXPLORER”
2018	Received order of Phase II Mombasa Port Container Terminal Construction Project
2019	Head Office relocation (Aomi, Koto-ku to Kandajimbocho, Chiyoda-ku)
2020	Announcement of three-year business plan (FY 2020-2022)