Objective: To investigate the expression of metastasis-associated in colon cancer-1 (MACC-1) mediated by siRNA, and to study the effects of its downregulation on cell proliferation, cell cycle and invasion ability of cervical cancer SiHa cells., Methods: MACC-1 siRNA and control siRNA were transfected into cervical cancer SiHa cells, and the expression of MACC-1 protein after transfection with MACC-1 siRNA was detected by Western blotting. The changes of cell proliferation, cell cycle and invasion ability of the SiHa cells were determined by CCK-8 kit, flow cytometry and Boyden chamber assay. The expressions of cell cycle- and invasion-related proteins were analyzed by Western blotting., Results: Compared with the untreated group (0.317 ± 0.023) and control siRNA group (0.309 ± 0.021), the expression of MACC-1 protein was downregulated in the MACC1 siRNA group (0.041 ± 0.006) (P < 0.05), and its downregulation significantly suppressed the cell proliferation, altered the cell cycle distribution and reduced the cell invasion ability of the SiHa cells (P < 0.05). Compared with the untreated group (0.217 ± 0.025 and 0.215 ± 0.024) and the control siRNA group (0.222 ± 0.023 and 0.207 ± 0.027), the expression of cyclin D1 and Cdk2 proteins were significantly decreased in the MACC1 siRNA group (0.076 ± 0.010 and 0.039 ± 0.007) (P < 0.05). Compared with the untreated group (0.099 ± 0.007) and control siRNA group (0.105 ± 0.012), the expression of p21 protein was significantly increased in the MACC1 siRNA group (0.676 ± 0.044) (P < 0.05). The downregulation of MACC-1 expression also evoked a decrease of expressions of MMP-2 and MMP-9 proteins and an increase of E-cadherin protein expression (P < 0.05)., Conclusions: MACC-1 downregulation-mediated inhibition of proliferation and decreased invasion ability of tumor cells may be closely associated with the alterations of expressions of cell cycle- and invasion-related proteins.