She was the winner of the gold medal in the 1500 meters and the silver medal in the 1000 meters at the 2005 World Championships, as she ended up as the overall champion. At the 2006 World Championships, Jin won the 1000, 1500, and 3000 meters on her way to a second consecutive overall championship. She also finished first in the overall World Cup standings for the 2005-2006 season.
At the 2006 Winter Olympics, she won three gold medals, winning women's individual 1000 meters, and 1500 meters events, and as a member of the South Korean women's victorious 3000 meter relay team. In doing so, Jin became the first athlete (by less than half an hour) from Korea to win three gold medals in one Olympics. Ahn Hyun-Soo matched Jin's achievement later by helping Korea to win men's 5000 meters relay.