Zhang Yiyuan is not a private enterprise. 199 1 year Zhang Yiyuan tea house was transformed into a state-owned enterprise, and the trademark of Zhang Yiyuan was officially registered. 1992, in order to adapt to the changes in the new market environment, the state decided to set up Beijing Zhang Yiyuan Tea Company on the basis of Zhang Yiyuan Teahouse. 1993 Zhang Yiyuan was named as an old Chinese brand by the Ministry of Internal Trade. 1993.