Abstract: Objective To investigate the diagnostic significance of carbonhydrate anitigen 15-3,(CAl5-3), carcinoembryonic antigen(CEA) combined with whole body bone scan(WBS) for bone metastases in patients with breast cancer. Methods Serum levels of CA153 and CEA were measured and WBS was performed in 92 breast cancer patients. Results Serum levels of CA153 and CEA were higher in bone metastases group than in without bone metastases group significantly(CA15.3:t=91.8342; CEA:t=77.6323,P<0.01). The sensitivity and specificity of combined determinations of CA153, CEA and WBS were 95.74% and 88.89% respectively, its diagnostic efficiency was higher than any one of them. Conclusion The combined detection of CA153, CEA and WBS can improve the diagnostic efficiency of bone metastases in patient with breast cancer, especially when the results of bone scanning is equivocal.