Gloria started playing golf at the age of 13. Though born in Korea, her family moved to Australia when she was a teenager. It was there she honed her skills, becoming a top junior player and representing Australia on the National Team. She also won the Australian Junior Championship three times, and broke several of Karrie Webb's junior records in the process.

After turning pro in 1998, Gloria quickly won her first professional tournament on the KLPGA tour. The following year, she came over to America, where a tie for 13th at Q-School earned her exempt status on the 2000 LPGA tour. Still only 19, her rookie year on the LPGA was not particularly impressive, but she improved markedly in her second year on tour. Still, she was playing at a middling level until late in the season. All of a sudden, she caught fire, notching her first top ten at the Canadian Open, then just a few weeks later shooting her career best 64 in winning her first tournament on the LPGA tour, the Williams Championship. Then just as suddenly, she faded again, those two top tens being the only two she managed in 2001.

2002 started with a bang, with a third place at the first event of the year, the Takefuji Classic. She did not have another truly decent tournament for several months after that, however. But as the summer arrived, she posted a few good finishes, then came out of literally nowhere to contend at the Sybase Big Apple Classic. Her 63 in the third round there put her into a tie for the lead with none other than Annika Sorenstam, but despite playing against the tour's #1 player the entire final round, it was Gloria who came out on top, tied after regulation ended with fellow Korean Hee-Won Han. Gloria put it away with a birdie on the first playoff hole, and grabbed her second win.

Gloria finished the season just out of the top 20 on the money list, yet her consistency was still not as great as the other top Koreans, with only 5 top tens.

Gloria slumped again throughout most of 2003, notching an occasional good finish, but otherwise not playing up to her standards. Then, towards the end of the season, she caught fire, scoring her first top ten in a Major at the British Open. She followed that with a blistering 62 in the final round of the CJ 9 Bridges Classic to leapfrog from 27th place to a tie for 2nd. This score tied for best ever achieved in a third round in the LPGA.

Gloria finished the year in 34th place on the money list, but with momentum heading into 2004. But the 2004 season was much like her previous ones. Although she had her best scoring average, and finished 27th on the money list, she was still not able to maintain consistency throughout the season. Nonetheless, she did manage her best ever finish in a Major, a tie for 4th at the LPGA Championship, and her return to the top 30 indicated she was ready to take a big leap in her career.

Which, indeed, happened in 2005. Despite struggling with numerous injuries all through the year, she easily managed her career best season in 2005. She notched ten top tens, and had several good chances to win tournaments. Although a victory eluded her, she still won more than $800,000 in a season for the first time in her life, had her best ever scoring average, and finished 9th on the money list, the first time she had ever finished inside the top 20.

Gloria startled everyone by starting 2006 with the announcement that she was getting engaged. She also said that she was not sure she would continue playing golf once she was married, but would wait and see how it went. The year did not start well; her grandfather died during the year's second event, and she took time off to deal with that, then took a while to get back into form. Towards the end of the year, she started to play well again, and wound up in 25th place on the money list.

In December of 2006, Gloria got married to Hee Taek Chang, whom she had met back when she lived in Australia, before she turned pro. She reconnected with him in 2004, when she was playing the CJ 9 Bridges Classic on Cheju Island. A romance developed, eventually leading to marriage. After their honeymoon, she returned to work, preparing herself for another season on the LPGA.

2007 was one of Gloria's weaker seasons on tour, with only one top ten all year. She finished outside the top 50 on the money list as well. However, the distraction of getting married probably accounts for a lot of that. 2008 was even more of a struggle, with Gloria not even making a top twenty on tour through October, and missing the cut quite often.