Objective To study the clinicopathological characteristics of breast cancer in Western China.Methods: All the data of breast cancer patients (12262) registered in the Western China Clinical Cooperation Group (WCCCG), from 2008 to 2012, were analyzed.Results:The mean age at diagnosis for female breast cancer were 47.6 years and peaked in age group 40-49 (36.4%)and 50-59 (26.0%) years, with 50.9% in the pre-menopausal stage.Male breast cancer accounted for about 0.34% of breast cancer cases.About 55.45% of female cases were found to have pregnancy no less than 2 times,22.52% and 21.54% only had 0 and 1 time pregnancy, respectively; whlie 34.72 % had no less than 2 times production, 21.00% and 44.12% had 0 and 1 time production, respectively.The 1st and 2nd highest frequency of age at menarche was observed in the female age group of 13 years (24.69%) and 14 years (24.14%),respectively.About 63.8% (6,159 / 9,905) of breast cancers were ER positive and 56.2% (5,546 / 9858) were PR positive.Chemotherapy was the main therapeutic option of preoperative neoadjuvant and postoperative adjuvant therapies (33.1% & 84.0%), with endocrinotherapy (0.40% & 29.3%), radiotherapy (0.23% & 20.0%) and targeted therapy (0.02% & 1.08%) as the 2nd to 4th therapeutic options, respectively.Conclusion:Screening examination for breast cancer needs to be carried out at earlier ages in Western China than in developed countries and combined therapies are of great unmet needs.