Chiang was re-elected to the Legislative Yuan in 2004 but did not take on the vice president post, which went to the KMT's alliance People First Party.

In March 2005, Chiang led the KMT's first official delegation to mainland China since the end of major hostilities in the Chinese Civil War in 1949.

The delegation paid homage to the 72 martyrs of the Tenth Revolution in Huanghuagang before travelling to the Sun Yat-sen Mausoleum in Nanjing and to Beijing.

Following the Kuomintang's landslide win in the presidential election in 2008, Chiang was designated as chairman of the Straits Exchange Foundation, the semi-official body responsible for negotiation on non-political matters with the People's Republic of China.

[2][3] He died of multiple organ failure at Mackay Memorial Hospital in Taipei on 10 December 2018.