Born in Kaohsiung, Chang was a physician who graduated from National Taiwan University as an MD in 1967. He worked in the university hospital as a part-time attending physician from 1976 to 1977. He then worked in the Chang Gung Memorial Hospital from 1976 to 1999, and since 1997 as its president. Chang is the author of sixteen and coauthor of 167 scientific citation index papers.
Chang ran as an independent vice-presidental candidate (on the ticket of James Soong) in the 2000 elections.
He is married to Lee Fang-hui (李芳惠) with two sons.
See also: Politics of Taiwan