Objective：To investigate the expression of RNA binding motif protein 7（RBM7）in human breast cancer cell MDA-MB- 231，and its effects on the expression of A-kinase anchoring protein 12（AKAP12）. Methods：MDA-MB-231 cells were transfected with lentiviruses for RBM7 overexpression，knockdown（experimental group）and the corresponding control lentivirus（control group） respectively. Stable transfected cell lines were selected with puromycin and verified via fluorescence microscopy. The expression of RBM7 after transfection was verified by qRTPCR and Western blot experiments，respectively，and the effect of RBM7 expression change on AKAP12 expression was observed. Gene ontology（GO）enrichment analysis was performed on the differentially expressed genes obtained by RNA-sequence，and revealed significantly enriched pathways regulated by RBM7. At the same time，the UALCAN database was employed to assess AKAP12 expression in breast cancer. The relationship between RBM7 and AKAP12 was studied by RNA binding protein immunoprecipitation（RIP）assays. Furthermore，immunohistochemicalanalysis was performed to delineate the relationship between RBM7 and AKAP12 in breast cancer tissues. Results：After transfecting MDAMB-231 breast cancer cells with lentiviruses for RBM7 overexpression and knockdown respectively and screening with puromycin for 2 weeks，stably transfected cell lines with RBM7 overexpression and knockdown were obtained. GO enrichment analysis of differentially expressed genes obtained by RNA-sequence revealed that the genes significantly affected by RBM7 were mainly enriched in the cell cycle pathway. Moreover，the UALCAN database analysis showed that AKAP12 was lowly expressed in breast cancer（P ＜ 0.05）. It was observed that overexpression of RBM7 could downregulate RNA and protein expression of AKAP12，and knockdown of RBM7 upregulated RNA and protein expression of AKAP12 via qRT -PCR and Western blot（P ＜ 0.05）. RIP assays revealed that RBM7 could directly bind to mRNA of AKAP12（P ＜ 0.05）. Immunohistochemical analysis also showed that there was a significant negative correlation between the expression of RBM7 and AKAP12 in human breast cancer tissues（P ＜ 0.05）. Conclusion：RBM7 downregulates the expression of AKAP12 in breast cancer cell MDA-MB-231 and breast cancer tissues.