Homicide detectives have been called in to investigate the disappearance of a Sydney woman who has been missing since Friday night.

Police say they hold "grave concerns" for the safety of Qi Yu who was last seen about 7.30pm at an apartment she shares with friends in Campsie.

The 28-year-old had communicated with family in China about 15 minutes earlier but has not been seen or heard from since.

Friends and family have told police this is out of character and now fear for her safety.

Police have since located her car in Lindsay Street, Burwood, about four kilometres from her home.

Police are urging anyone who may have seen the vehicle, which has the registration plate DLK-13P, between 7:00pm on June 8 and 8:30pm on June 9, to come forward.