She's abrasive, afraid of commitment, doesn't "do" emotion and is extremely competitive about getting the "cool" surgeries. She is of Korean descent and is a native of Beverly Hills, Calif. Cristina graduated from the Stanford University School of Medicine and maintains a love-hate relationship with her mother.
Despite being his polar opposite in many respects, she began dating Dr. Preston Burke during Season One. She became pregnant, only to have him break off their relationship for professional reasons.
Cristina planned to have an abortion without telling Burke, but changed her mind after talking to a pregnant patient. She later collapsed during a surgery with Dr. Burke, and was quickly diagnosed with an ectopic pregnancy, which was surgically terminated.
Despite his emotional and physical trauma, she and Burke got back together soon after. The evolution of Cristina's relationship with Dr. Burke is a focal point of the first three seasons Grey's Anatomy.
Cristina, who is particularly close to Meredith, although she is also friends with George and Izzie, only told Burke she loved him while he was asleep, and didn't give up her apartment for months after moving in with him.
In Season Three, she helped Preston cover up a hand tremor (resulting from his being shot at the end of Season Two) that should have kept the surgeon on the shelf, but which he attempted to simply work in spite of.
While this caused strife between them, they later patched things up, and became engaged. However, Burke left Cristina at the altar after realizing she was only marrying him because he wanted to - not because she wanted to.
Now she's free - damn it - and Cristina picking up the pieces of her life will be one of the most interesting things to watch in Grey's Anatomy's fourth year.