She made her entertainment debut as a member of the K-pop girl group Fin.K.L, along with Lee Hyori, Ock Joo-hyun, and Sung Yu-ri.

She sang Eco's "Heng Bok Han Na Reul" and was immediately selected to be in the group.

On the show, Lee signalled that she had grown into a "lady" from her Fin.K.L teenage days via a change in her hairstyle and clothes.

In 2010, Lee also appeared in Heroes where 12 artists competed in games to garner the popular title or will fall into the unpopular group.

Lee Jin is a playable character in the video game Tony Hawk's Pro Skater 2 (only in the South Korean PC version).