Objective To investigate the changes and clinical significance of serum thymidine kinase 1(TK1) ,carbohydrate antigen 153 (CA153) and carcinoembryonic antigen(CEA) in the patients with breast cancer .Methods The levels of serum TK1 ,CA153 and CEA were detected in 92 inpatients with breast cancer ,66 patients with benign breast disease and 50 people undergoing the physical examination . The relationship between serum TK1 ,CA153 and CEA with the pathologic parameters in breast cancer was analyzed by the single factor a‐nalysis method .Results Serum TK1 ,CA153 and CEA levels in the breast cancer group were significantly higher than those in the benign breast disease group and control group ,the differences were statistically significant(P<0 .05) .The serum TK1 ,CA153 and CEA levels were related with the degree of pathological stage and lymph node metastasis(P<0 .05) .Conclusion The increase of serum TK1 ,CA153 and CEA levels has an important clinical significance in the diagnosis ,infiltration ,metastasis and severity of breast cancer .