Abstract: Objective To study the effect of selective COX-2 inhibitor celecoxib on the proliferation, apoptosis, invasion and adhesion of triple negative breast cancer stem cells, and its mechanism. Methods CCK-8 method was used to detect cell activity. AV-PI double staining method was used to identify cell apoptosis. Cell adhesion experiment was used to test the cell adhesion after treatment. Transwell invasion assay was used to detect the inhibitory effects of celecoxib on stem cell invasiveness. Results Celecoxib could signifi cantly induce the apoptosis of triple- negative breast cancer stem cells(P<0.05). The differences among different concentration groups, and different times at the same concentration were statistically signifi cant. Compared with the control group, the adhesion to Matrigel gel in treated groups was signifi cantly suppressed,and the number of invasive cells in treated groups was remarkably decreased in Transwell invasion assay(P<0.05). Conclusion Selective COX-2 inhibitor celecoxib could inhibit the proliferation, adhesion and invasiveness and induce the apoptosis of triple-negative breast cancer stem cells in a dose- and timedependent manner in vitro.