Breast cancer is a common malignancy, and it is the second leading cause of cancer-related death among women worldwide. The pathogenesis of breast cancer is poorly understood, leading to unsatisfactory efficacy of current anti-PC therapies. The aim of this study is to investigate the role of LncRNA HOTAIR in proliferation, apoptosis, migration and invasion of human breast cancer cell line MCF-7. MCF-7 cells were cultured and transfected with HOTAIR siRNA, and the proliferation rate of cells was determined using MTT and colony-forming assay; moreover, the apoptosis as well as cell cycles were determined using annexin V/propidium iodide staining methods and analyzed using flow cytometery; furthermore, cell scratch and transwell assays have been performed to examine the migration and invasion of MCF-7 cells; Next, cells were collected, and RT-qPCR as well as western blotting assay were performed to examine the expression of P53, MDM2, AKT, JNK, MMP-2 and MMP-9. We discovered that knockdown of HOTAIR induced significant decrease in proliferation and increase in apoptosis of MCF-7 cells, and the cell cycles of HOTAIR siRNA transfected cells have been arrested at G1 phase (p<0.01); moreover, knockdown of HOTAIR lead to marked decrease in the migration and invasion ability of MCF-7 cells; finally, knockdown of HOTAIR induced significant decrease in the expression of P53/Akt/JNK (p<0.01), and significant increase in the expression of P53 in MCF-7 cells (p<0.01). In conclusion, our results proved that HOTAIR may regulate proliferation, apoptosis, migration and invasion of MCF-7 cells through regulating the P53/Akt/JNK signaling pathway.