|Oct. 3, 2005||Mitsubishi Chemical Holdings Corporation was jointly established by Mitsubishi Chemical Corporation and Mitsubishi Pharma Corporation, by means of a stock-for-stock exchange effective October 1, 2005.|
|Oct. 10, 2006||The head office relocated to Shiba 4-chome, Minato-ku, Tokyo.|
|Oct. 1, 2007||Mitsubishi Plastics, Inc. became a wholly-owned subsidiary of Mitsubishi Chemical Holdings Corporation.
Mitsubishi Pharma Corporation and Tanabe Seiyaku Co., Ltd. merged and became a listed subsidiary of Mitsubishi Chemical Holdings Corporation as Mitsubishi Tanabe Pharma Corporation.
|Apr. 1, 2008||Functional products businesses of Mitsubishi Chemical Corporation, Mitsubishi Plastics, Inc., Mitsubishi Polyester Film Corporation, Mitsubishi Chemical Functional Products, Inc., and Mitsubishi Chemical MKV Company were amalgamated to become a consolidated new company, Mitsubishi Plastics, Inc.|
|Apr. 1, 2009||The KAITEKI Institute, Inc. was established.|
|Mar. 30, 2010||Mitsubishi Rayon Co., Ltd. became a consolidated subsidiary of Mitsubishi Chemical Holdings Corporation.|
|Nov. 29, 2010||Mitsubishi Chemical Holdings America, Inc. was established.|
|Jan. 17, 2011||Mitsubishi Chemical Holdings (Beijing) Co., Ltd. was established.|
|Jun. 1, 2012||MCFA Inc. became a consolidated subsidiary of Mitsubishi Chemical Holdings Corporation.|
|Jul. 2, 2012||The head office relocated to Marunouchi 1-chome, Chiyoda-ku, Tokyo.|