| 1992. 06. |
Established (464-3 Jangan-dong Dongdaemun-gu, Seoul, KOREA) |
| 2002. 05. |
Acquired ISO 9001 (KFQ) |
| 2006. 11. |
Awarded the Grand Prixe in Promote Construction Cooperation (MOLIT) |
| 2007. 10. |
Obtained Overseas Construction Liscense (HVAC) |
| 2011. 04. |
Established Younchang do Brasil Ltda. in Sao Paulo, Brazil |
| 2011. 08. |
Established Branch Office in Abu Dhabi ,U.A.E |
| 2014. 09 |
Established Younchang Mexico in Monterrey, Mexico |
| 2014. 09. |
Moved H/Q (30 Backjegobun-ro 41-gil Songpa-gu, Seoul, KOREA) |
| 2015. 05. |
Acquired ISO 14001 (AKR) |
| 2015. 05. |
Acquired OHSAS 18001 (AKR) |
| 2015. 06. |
Established Younchang USA in Atlanta, USA |
| 2016. 03. |
Established Branch Office in MOROCCO |
| 2016. 08. |
Established Younchang Engineering INDIA (PVT) LTD in Chennai, INDIA |
| 2016. 09. |
Established Younchang Engineering S.L (PVT) LTD in SRI-LANKA |
| 2017. 07. |
Established Younchang Engineering Vietnam In VIETNAM |
| 2018. 02. |
Established Younchang LLC, in Duqm, Oman |
| 2018. 05. |
Established (Younchang Hungary KFT.) in HUNGARY |
| 2019.06. |
Began Operation of Younin Plant Factory |
| 2022. 04. |
Established Younchang Poland sp. z o.o. in POLAND |
