Lee was born in the Haenam County, South Korea and grew up in Bundang. In 2002, Lee successfully signed a contract with S.M. Entertainment after she won the category of "Best Feature" in the S.M. Entertainment Best Youth contest. For the contest, she acted out a monologue, singing to Dana The Grace's "Until the End of the World", and also did freestyle modeling poses. After she joined the company, she began intense training lessons on acting, singing, and dancing.