This was a hospital-based, nationwide retrospective epidemiologic study, from 1999 to 2008 in China, of patients with breast cancer.A total of 1009 (27%) of the 3732 randomly selected patients received radiotherapy.Radiotherapy use increased significantly from 1999 to 2008 and varied between different hospitals; it decreased with increasing age and decreasing stage.Radiotherapy use was low and should be improved.Background: To investigate the use of radiotherapy (Rr) in China in patients with breast cancer over a 10-year period.A hospital-based, nationwide, multicenter, retrospective epidemiologic study of women with primary breast cancer was conducted.Patients and Methods: Patients were selected randomly in 7 hospitals from 1999 to 2008.Data on overall RT, postmastectomy RT (PMRT), RT after conservative breast surgery (PBRT) and palliative RT (PRT) were recorded.RT use was analyzed, and differences were compared by using the Cochran-Armitage trend test and the x2 test.A total of 3732 patients were included: 1009 (27%) received RT, including 688 (18.4%) PMRT, 170 (4.6%) PBRT, 86 (2.3%) PRT, 47 (1.3%) both PMRT and PRT, and 18 (0.5%) other RT.Results: Overall use of RT increased significantly from 1999 to 2008 (2P <.001).There was a slight but significant increase in PMRT (2P =.012) and a 10-fold increase in PBRT (2P <.001); use of PRT was relatively constant (2P =.777).There was a significant difference among regions in the use of RT, PMRT, PBRT, and PRT (2P <.01).Of patients with stage Ⅲ disease, 51.6% and of those with node-positive stage Ⅱ disease treated by radical mastectomy, 21% had received PMRT.In patients treated by using breast conservative surgery, 83.7% received PBRT, which was not affected by stage.Conclusion: In summary, in China, the overall use of RT in patients with breast cancer was quite low, but there was an increasing trend in those treated between 1999 and 2008.