Ji Sung made his screen debut as ‘Kang Dae-wook’ in the 1999 television romance drama series ‘Kaist.’ He continued on to appear in television series like ‘Popcorn’ (2000), ‘I Want to Keep Seeing You’ (2000), ‘Delicious Proposal’ (2001), ‘Open Drama Man & Woman’ (2001), and ‘Wonderful Days’ (2001). He made his silver screen debut in the 2002 comedy film ‘Whistling Princess,’ directed by Jeong-hwan Lee. He was next seen in television series like ‘All In’ (2003), ‘The King's Woman’ (2003), ‘Save the Last Dance for Me’ (2004), ‘Beating Heart’ (2005), ‘New Heart’ (2007), ‘Swallow the Sun’ (2009), ‘Kim Su-ro, The Iron King’ (2010), ‘Royal Family’ (2011), and ‘The Great Seer’ (2012). In 2013, he played the role of ‘Jo Min-hyuk’ in the South Korean television series ‘Secret Love.’ The show ran for 16 episodes and Ji Sung bagged 3 KBS Drama Awards for his performance in the series. He next appeared in the 2015 South Korean television series ‘Kill Me, Heal Me,’ created by Han Hee. Ji Sung portrayed several characters in the series, including ‘Lee Do-hyun,’ ‘Shin Se-gi,’ and ‘Mr. X,’ which earned him 4 ‘MBC Drama Awards.’ He was next seen in television shows like ‘Entertainer’ (2016), ‘Innocent Defendant’ (2017), and ‘Familiar Wife’ (2018). In 2018, he portrayed ‘Heungseon Daewongun’ in the South Korean period film ‘Fengshui,’ directed by Park Hee-gon. The film received mixed reviews from critics. Ji Sung was last seen playing the role of ‘Kang Yo-han’ in the 2021 South Korean television series ‘The Devil Judge,’ directed by Choi Jung-gyu. He is all set to appear in the upcoming South Korean television series ‘Adamas’ where he will portray ‘Ha Woo-shin / Song Soo-hyun.’