Dr. Cristina Yang (Sandra Oh) from "Grey's Anatomy" is a surgical resident at Seattle Grace Hospital (SGH). She grew up in Beverly Hills, California and graduated first in her class from Stanford University Medical School. She is known for being extremely competitive and one of the most talented residents at the hospital. She wants to specialize in cardiothoracic surgery, in part because she watched her biological father bleed out in front of her when they in a car accident when she was nine. She is best friends with Dr. Meredith Grey (Ellen Pompeo) who she refers to as "her person."
In Season 1, Cristina is a member of the incoming intern class at SGH and quickly befriends fellow intern Meredith Grey. She also starts a relationship with an attending physician, Dr. Preston Burke (Isaiah Washington). At the end of the first season she realizes she is pregnant and schedules an abortion.
At the beginning of Season 2, Cristina makes an effort to avoid Burke because she does not want to tell him about her pregnancy. After Burke becomes concerned that their relationship will prevent him from becoming Chief of Surgery, he breaks up with her. Cristina is devastated but pretends not to be hurt. When she collapses during a surgery, it is revealed that she is suffering from an ectopic pregnancy. She miscarries the baby but resumes her relationship with Burke. During the rest of Season 2, their relationship gradually becomes more serious and Cristina moves in to his apartment. In the Season 2 finale, Burke is shot outside of the hospital and she runs away because she is unable to deal with the possibility of losing him.
During Season 3 Cristina spends the first part of the season helping Burke hide the fact that he has developed a hand tremor that prevents him from performing surgery. For a while the two manage to keep the secret by having Cristina scrub in on all of Burke's operations but the secrecy eventually gets to her and she confesses to the chief, Dr. Richard Webber (James Pickens, Jr.). Following her confession, Burke and Cristina refuse to speak to each other but he eventually ends the cold war by proposing marriage which she accepts. However in the season finale Burke abandons Cristina at the altar because he realizes that he has forced her to change too much. When she arrives at their apartment she realizes Burke has left town for good.
During Season 4 Cristina copes with Burke's departure. This task is made harder by the fact that the new cardio attending Dr. Erica Hahn (Brooke Smith) hates her and will not allow her to scrub in on any cardio operations. The one bright spot is that she develops a friendship with Dr. Callie Torres (Sara Ramirez) and the two eventually become roommates.
During Season 5 Cristina meets Dr. Owen Hunt (Kevin McKidd), who served as a doctor in Iraq. He eventually takes a position as head of trauma surgery at SGH. Although they begin a relationship, Owen's post traumatic stress disorder (PTSD) becomes an issue after he accidentally tries to strangle her while laying in bed one evening. Cristina admits to Owen that she is scared to be with him and they break up. Owen eventually begins therapy to deal with his PTSD. By the end of Season 5 the two have reunited and are in a healthy relationship.
In Season 6 Cristina is still depressed by the fact that she lacks a good mentor and that there are few cardio surgery opportunities. Owen invites his former Army colleague Dr. Teddy Altman (Kim Raver) to join SGH as the new cardio attending. Although Cristina is thrilled to have a mentor, she is not aware that Teddy has feelings for Owen. Unable to deal with the fact that Owen invited her to Seattle to help his girlfriend, Teddy tells Cristina that she is leaving SGH. Cristina begs her to stay and asks what she wants in return for staying. When Teddy tells her that she wants Owen, Cristina responds that she can have him. Later, Cristina is shocked by her statement. When Owen learns what happened he tells Cristina that their relationship matters and that he won't allow her to give up on them. In the season finale, Cristina performs life saving surgery on Dr. Derek Shephard (Patrick Dempsey) after he is shot by a gunman who has targeted the hospital.
"Okay, let me get this straight. You don't just celebrate Christmas... you actually believe in Santa Claus?"
"Meredith, this is Fight Club! Nobody talks about it!"
"This... is where I live. My mother decorated it. I don't do laundry, I buy new underwear. See, and uh, under the table? Six months of magazines I know I'll never read, but I won't throw out. I don't wash dishes, vacuum, or put the toilet paper on the holder. I hired a maid once, she ran away crying. Uh... the only things in my fridge are water, vodka, and diet soda. And I don't care, but you do. Still think living together is a good idea?"