| 1987.03 | Established YEGONG Trading |
| 1996.05 | Changed to Corporate ( YEGONG TRADING Co., Ltd ) |
| 1998.03 | Changed company name to SEPOONG POLYMER Co., Ltd |
| 2002.03 | Opened an agency in Thailand |
| 2004.03 | Established affiliate SEPOONG TM Co.,Ltd |
| 2004.10 | Opened an agency in Young-nam area in Korea |
| 2005.01 |
Opened an agency in Ho-nam area in Korea Entered into contract for representative of CLAX ITALIA |
| 2006.02 | Established chemical board and resin factory (Bu-Pyeong, Inchon) |
| 2006.04 | Moved head office to Mario tower, Gu-ro |
| 2007.09 | Certification of ISO 9001, 14001 |
| 2009.12 | Increased capital stock to $200,000 from $100,000 |
| 2010.02 | Certification of MAIN-BIZ |
| 2010.03 | Transferred Head Office and Factory to Hwasung Province, Increased Capacities |
| 2011.01 | Established Mokpo subsidiary |
| 2011.05 | Established R&D center in Headquaters |
| 2012.07 | Established the Precision Machining Centre |
| 2013.06 |
Acquired Patent for Molding Machine Starting of CM Department new business |
| 2013.09 | Acquired Patent for UV Curable manufacturing |
| 2013.12 |
Acquired Patent for the manufacturing method of Mold(MPR) Acquired Patent for UV Curable Prepreg compositions and manufacturing method Opened an prototype materials agency in Young-nam area |
| 2014.04 |
Acquired Patent for sandable epoxy resin composite and Molding method for spray Increased capital stock to $300,000 from $200,000 |
| 2014.07 |
Transferred Headquaters to Doksan, Gum-Chon Transferred Factory to Yanggam, Hwasung, integration the factory and extension new business, increased capacities (prototype materials and composite materials manufacture, precision machining, 5 Axis machining for a large size, UV prepreg manufacture) |
| 2014.12 | Purchased 5 Axis machine |
| 2015.06 | Acquired KR classification, application for a ship or a ship goods |
| 2016.02 | Certification of MAIN-BIZ |
| 2016.09 | Certification of Quality Management System, Environment Management System |
| 2016.11 | Design registration of resin and board for automobile tire master mold |
| 2017.03 | Conclusion of technical implementation contract for Korea Ship Safety Technology Authority |
| 2017.06 | Addition of manufacturing other ship, entertainment and sports boat manufacturer |
| 2017.09 | Patent registraion of semi-non-combustible urethane foam |
| 2018.01 | Certification of KR classification (Acquired a special ship manufacturer) |