Updated project metadata. Breast cancer is the leading type of cancer in women. Breast cancer brain metastasis is considered as an essential issue in breast cancer patients. Membrane proteins play important roles in breast cancer brain metastasis that contributes to the cell adhesion and penetration of blood-brain barrier. To achieve a deeper insight of the mechanism of breast cancer brain metastasis, liquid chromatography tandem mass spectrometry (LC-MS/MS) was performed to analyze the enriched membrane proteomes from six different breast cancer cell lines. Quantitative proteomic data of all cell lines were compared with MDA-MB-231BR which has the specific brain metastasis capacity. 1239 proteins were identified and 990 were quantified with more than 70% of membrane proteins in all cell lines. Each cell line can be separated apart from others in PCA. Ingenuity pathway analysis (IPA) supported the high brain metastatic ability of 231BR and suggested importance of the up-regulation of integrin proteins and down-regulation of EPHA in brain metastasis. 28 proteins were observed unique expression alteration in 231BR. The up-regulation of NPM1, hnRNP Q, hnRNP K and eIF3l and the down-regulation of TUBB4B and TUBB were observed to be associated with the brain metastasis cell line and may contributes to the breast cancer brain metastasis.