She began performing when she appeared in music videos as early as 2002. She made her true acting debut, however, in 2004 with a large role on the television show Nonstop 5. The show, which had run for many seasons, was a fan favorite, and immediately boosted her popularity. In addition, she sang a song for the show's soundtrack.

In 2006, after acting in another three television series, she got her first lead role on the television series Pure in Heart. She followed up this success with another lead role on a different show, called The King and I.

In 2008, she got her third lead role on the television show Strongest Chil Woo. However, it was not until the following year, when she got the lead role in the show Boys Over Flowers, that she truly became a star. The show was a huge hit with fans and critics alike. Since then, she has acted in another six television shows. She has also directed several films and has written three books.