She attended an all-female high school before gaining early admission to Chung-Ang University, where she studied computer science.

[citation needed] Ko first achieved wide recognition through her role in Beat (again with Jung Woo-sung), a film that caught the imagination of many South Korean high school students.

Her acting in the film was much praised and garnered the Best Actress prize from the local Grand Bell Awards ceremony.

[4] Then, after two years off, Ko returned in 2003 opposite Han Suk-kyu in the spy thriller Double Agent; however, the film failed to live up to the expectations of most viewers and critics.

[5] Ko married actor Jang Dong-gun in a star-studded wedding ceremony held at Seoul's Shilla Hotel on May 2, 2010, while five months pregnant.