Objective To analyze the differential protein expression of three negative breast cancer tissue before and after menopause application of iTRAQ technology, to explore the effects of menopause on three negative breast cancer. Methods Selected premenopausal and postmenopausal women with 8 cases in each by negative pathological diagnosis, differential protein analysis on significant function, difference of protein pathway and difference of protein verify were analyzed by the application iTRAQ technology. Results (1﹚Differential protein interactome was relatively centralized premenopausal, and postmenopausal differences of protein was much, and the distribution of the dispersed. (2﹚In pre menopausal cancer tissue protein differences existed in 5 of the significant difference in differences approach; post-menopausal cancer tissue protein existsed in 15 significantly different pathways. (3﹚Tumor adjacent tissues compared with premenopausal had a total of 214 significant difference proteins, postmenopausal had a total of 360 significant differ-ence proteins. The upregul ated proteins in 81 kinds of premenopausal three negative breast cancer tissues, 133 down regμl ated proteins, postmenopausal up-regμl ated protein 157 types, down 203. Conclusion Using iTRAQ technology to found that the expression has a certain particμl arity differences in three negative breast cancer before and after menopause, indicate three negative breast cancer may have different pathogenesis in the different estrogen environment, may be a new target for treatment of TNBC.