She started to train in boxing in 2002 for dieting and exercise when she was 19, and began an amateur career under coach Sang Kwon Park in 2002.
[5][6] In 2005 Choi traveled to China to face Maribel Zurita for the IFBA Flyweight World Championship and won by split-decision.
[7] Eight months later she successfully defended and won the IFBA Flyweight World Championship in Seongnam City against Jet Izumi of Japan.
[8] In 2006, she was awarded a Korean Presidential Citation from President Roh Moo-Hyun.
In 2007, with a record of nine fights and eight wins,[1] Choi fought Elena Reid in Temecula, California losing the title by decision.