Chang qualified for the Chinese Taipei squad, as a lone male athlete, in pistol shooting at the 2004 Summer Olympics in Athens. He managed to get a minimum qualifying score of 581 to gain an Olympic quota place for Chinese Taipei in the free pistol, following his outstanding eighth-place finish at the Worlds two years earlier. Chang got off to a disastrous start by shooting a hapless 569 out of a possible 600 in the 10 m air pistol, slipping further off to fortieth from a field of forty-seven shooters. Three days later, in the 50 m pistol, Chang continued his Olympic flop from a bitter air pistol defeat to launch a dismal 548 in the qualifying round, forcing him in a thirtieth-place tie with 52-year-old Argentine shooter Maximo Modesti.