Lee competed in the Continental Cup from 1999 to 2004. Since 2004 she has mainly participated in the cross-country skiing Far East Cup . She has had 20 victories so far and won the overall standings in the 2009/10 , 2016/17 and 2019/20 seasons. In the 2008/09 , 2010/11 and 2014/15 season she finished second in the overall ranking. She ran her first World Cup race in November 2001 in Kuopio , which she finished classically with 89th place over 10 km. Her best result at the 2002 Winter Olympics in Salt Lake City was 46th in the 15 km mass start race. At the Nordic World Ski Championships in 2005 in Oberstdorf , she finished 49th over 10 km freestyle. Her best placement at the 2006 Winter Olympics in Pragelato was 57th place in the 15 km skiathlon race . At the Nordic World Ski Championships in Sapporo in 2007 , she reached 51st place over 10 km freestyle. In December 2008 she achieved 43rd place in the 15 km mass start race in La Clusaz , her best individual World Cup result to date. At the Nordic World Ski Championships in Liberec in 2009 , she finished 75th in the sprint and 63rd place over 10 km classic. Her best result at the 2010 Winter Olympics in Vancouver was 53rd place in the 10 km freestyle. At the 2011 Asian Winter Games , she won gold in the 10 km freestyle. At the Nordic World Ski Championships 2011 in Oslo , she reached 69th place in the sprint and 47th place in the 15 km pursuit race. Her best result at the 2014 Winter Olympics in Sochi was 36th place in the 30 km mass start race. At the Nordic World Ski Championships in Falun in 2015 , she finished 60th in sprint and 50th in skiathlon. In summer 2015 she started in the Australia / New Zealand Cup . She achieved two podium finishes, including a win, and finished fifth in the overall standings. At the Nordic Opening in Ruka at the beginning of the 2015/16 season she came in 74th place. In February 2017 she got her first World Cup points in Pyeongchang with 12th place in the skiathlon. At the Winter Asian Games 2017 in Sapporo, she won the bronze medal with the relay and the silver medal in the 15 km mass start race and the 10 km freestyle. In February 2018 she ran at the Winter Olympics in Pyeongchang to 57th place in the skiathlon, 51st place over 10 km freestyle and together with Ju Hye-ri to 21st place in the team sprint. The following year, she became the South Korean champion over 5 km classic and 10 km freestyle.
Note: This article places the family name before the person's first name. This is the usual order in Korean. Lee is the family name here, Chae-won is the first name.