Per Wikipedia:
Before Song debuted as an actress, she was a model for Kiki Magazine. She chose “Song Ji-hyo” as her stage name because she was inspired by the two famous actors Song Seung-heon and Song Hye-kyo, both main protagonists of Autumn in My Heart. Song then appeared in the music videos of Lee Soo-young‘s “And I Love You” and JTL‘s “Just Say Goodbye”.[2] She also made a cameo appearance in the television series Age of Innocence.