Choi began skating at age 10. From 2000, she was coached mainly by Shin Hea-sook in Seoul. She debuted on the ISU Junior Grand Prix series in late October 2002, placing 14th in Milan, Italy. She reached the free skate at the 2003 World Junior Championships in Ostrava by placing 13th in her qualifying group and 14th in the short program. She ranked 17th in the free skate and 18th overall.