Kang made her debut as a magazine model while in her first year of high school in 1997. In the late 1990s, she appeared in small roles in TV dramas and sitcoms while studying as a performing arts major at the Seoul Institute of the Arts. She gained notice in the art-house film Nabi but had her breakout role as Mido in the critically acclaimed and commercially successful Oldboy.
After numerous awards for Rules of Dating and Welcome to Dongmakgol, she was recognized as one of the best young actresses in the Korean film industry and continued to pick risky and quirky characters to play. She married rapper Tablo in 2009 and gave birth to their daughter, Haru, a year later.
