Her biggest breakthrough was in "My sassy girl" (2001), a romantic comedy that won her the Best Actress award at the Daejong Film Festival in 2002. In 2004, Jun starred in "Windstruck", a South Korean fantasy-romantic comedy. The film was a major success, ranking as the 8th-highest grossing Korean film of 2004. In 2006, she starred in "Daisy".
Since her debut as a model for Echo, Jun has modeled for many fashion companies and more recently, in advertisements for mobile phones and cosmetics. Some of her more popular product endorsements include Giordano, Laneige, and Samsung Anycall.
In 2005, she became the first Korean artist to feature on the cover for the famous fashion magazine ELLE.
Jun will play in the Chris Nahon directed live-action version of "Blood: the last vempire", which is to start filming in China and Argentina in March 2007.