Abstract: Abstract:Objective To investigate the etiological role of metastasis suppressor gene KAI1/CD82 genetic polymorphisms IVS（8）6C11A /6T11G in breast cancer. Methods A case-control study was taken on subjects included 109 breast cancer patients and 135 healthy individual controls.Genomic DNA was extracted from peripheral white cell of all subjects.The polymorphism was detected by a PCR-based DHPLC analysis and verified by DNA sequencing. Results The mutant allelotype 6T11G was 30.9% in healthy individuals group and was 32.1% in breast cancer group.There was no significant difference between the control group and breast cancer group(P>0.05),The value of 6T11G was not related to the age of the patients,and the histological gype,sive and histologic grading of tumors.Further statistics based on histological type revealed that significant difference existed in lymphatic metastasis (P<0.05). Conclusion The genetic polymorphism IVS（8）6C11A /6T11G in KAI1/CD82 gene may play a role in the lymphatic metastasis of breast cancer.Determination of this polymorphism may be suitable to identify the prognosis of breast cancer patients.