Objective:To study the expression and significance of COX-2 in triple-negative breast carcinoma(TNBC) and explore the relevance of COX-2 and neovascularization(MVD) marked by CD31. Methods:The expression of COX-2,MVD in 60 TNBC cases and 518 paraffin wax samples of non-TNBC patients were detected by immuno-histochemical method,and the clinical characteristics of TNBC cases and non-TNBC cases were compared. Results:①Compared with non-TNBC patients,TNBC cases were younger and mostly premenopausal patients,the differentiation of TNBC was lower while the percentage of histology graded Ⅲ was significantly increased;②The positive rate of COX-2 in 60 cases of TNBC was 73.3%,and that in 518 cases of the non-TNBC was 58.0%. The difference is statistically significant(P < 0.05);③In 60 cases of TNBC,the value of MVD(CD31 marked)was 183.73 ± 25.64,in 518 cases of non-TNBC,MVD was 168.84 ± 24.07(P < 0.01);④The expression of COX-2 in TNBC was significantly correlated with CD31(P < 0.01). Conclusion:The high expression of COX-2 and MVD are closely associated with infiltration and metastasis of TNBC,thus the abnormal expression of COX-2 and MVD are likely to participate together in the genesis and progress of TNBC.