Abstract: Objective To investigate the effect of HIF-1α gene silencing on the expression of TIMP1 and MMP1 in non-small cell lung cancer (NSCLC) A549 cells. Methods The siRNA-HIF-1α plasmid vector was transfected into A549 cells and cultured in hypoxic environment. The proliferation, migration and invasion of transfected cells were detected by MMT and Transwell. The expression of TIMP1, MMP1 mRNA and protein in the transfected cells were detected by real-time fluorescence quantitative and western blot. Results Compared with the control group, the expression of HIF-1α mRNA and protein in A549 group was significantly increased (P<0.05). Compared with the blank and si-NC groups, the expression of HIF-1α mRNA in si-HIF-1α group was significantly decreased (P<0.05). Compared with the blank group, the proliferation rate of si-HIF-1α group was significantly decreased at 24 h, 48 h and 72 h after the transfection (P<0.05). Compared with blank group, the migration and invasion of A549 cells in si-HIF-1α group were significantly decreased (P<0.05). Compared with blank group, the expression of MMP1 in si-HIF-1α group was significantly decreased, while the expression of TIMP1 was significantly increased (P<0.05). Conclusion HIF-1α siRNA can target silencing HIF-1α in A549 cells under hypoxia and inhibit cell proliferation, migration and invasion by down-regulating MMP1 expression and up-regulating TIMP1 expression.