In 1987, he was elected as the sole Deputy Speaker of the National Assembly after the United Democratic Party (UDP) decided to not put its candidate due to internal conflict.

After leaving politics, Jang established Dongseo University in 1991 and served as its chairman until 2008.

[1][2][3] Jang's widow, Park Dong-soon (born 1939), is the current chairwoman of Dongseo University.

[1][2][3] On 8 March 1988, Jang faced protests from opposition MPs after he and the DJP rushed a revised electoral law through without any agreements.

It was alleged that he set up around 5 billion won (approximately $5 million) in a Dongseo University slush fund and misappropriated it.