Han was first discovered at a teenage beauty pageant in 2003. She joined the ranks as a prominent Pan-Asian star due to the rising popularity of Spring Waltz (the fourth and final installment of Yoon Suk-ho's season drama series, following Autumn in My Heart, Winter Sonata and Summer Scent) in other Asian countries, including Indonesia, China, Taiwan, Hong Kong, Thailand, Singapore, Philippines.

The film called Ad-lib Night (a subtle drama by Lee Yoon-ki) follows a young single woman who rediscovers herself through an eerie overnight encounter with strangers. The film, in which she has the starring role, premiered in November 2006. She was then chosen for the title role in a daily soap opera called 하늘만큼 땅만큼 ("Like the Heavens, Like the Land), on KBS in January 2007.

Han was then cast in the SBS drama Iljimae,[2] which also stars Lee Jun-ki, Lee Young Ah, and Park Shi-hoo.

The independent film, Ride Away, in which Han portrayed Ha-jeong, debuted at the Jeonju International Film Festival in 2008.

In 2009 Han starred as the lead actress in the highly successful SBS drama, Brilliant Legacy, along with Lee Seung-gi. She was the runner-up to host the MnetT 20’s Choice Award on August 28 and was chosen due to the popularity of the SBS drama Brilliant Legacy. The drama's popularity with a peak viewership rating of 47.1% in South Korea has increased her visibility in the Korean media and popularity as an entertainment personality. Since the drama's conclusion, she has experienced a sharp rise in interest for endorsement deals and media requests for interviews.[3]

Following her success on Brilliant Legacy, Han was slated to assume the lead female role in the upcoming KBS2 drama Chuno. She, however, withdrew from the role prior to production allegedly due to issues relating to her management and salary.[4]

Han also stars in the collaborative Korean-Japanese telecinema production, Heaven's Postman, which was released in late 2009 (after several postponements).[5] The drama also features Kim Jaejoong[6] from TVXQ.

In September 2009 Han wrapped up her latest starring role in the musical drama, Soul Special, which also stars K. Will in his acting debut. The drama is slated to air in twelve five-minute segments on various online portals, with KBS airing the entire drama in four parts.[7]

She was meant to play the main role in the historical drama, Chuno, but she rejected it after having problems with the management; she was replaced by Lee Da-hae. Her most recent role was as the titular character in Dong Yi, MBC's 49th Anniversary Project.[8] Han won several acting awards for her portrayal as Choi Suk Bin.

Along with So Ji-sub, Han will star in Song Il Go's Only You. Production will begin March 2011 and is scheduled to premiere either summer or fall of 2011.[