Objective: The aim of this study was to study the inhibition effect of small interfering RNAs (siRNA) on gene expression in MG-63 cells,and to study the inhibitory effect on metastasis of MG-63. Methods: A plasmid of a short hairpin RNA targeting acid phosphatase 1 (ACP1) was constructed and transfected into MG-63 cell line. ACP1 expression of MG-63 cells before and after transfection was detected by RT-PCR and Western blot. The capacity of adhesion, migration and inva-sion was examined by adhesion assay, migration assay and transwell assay. Results: The recombinant plasmid pGenesit-1/ACP1-shRNA was successfully constructed, shRNA efficiently inhibited the expression of ACP1 by gene and protein level and suppressed cell migration. The adhesion decreased from 96.41±8.83 to 43.38±6.03 (P < 0.01), invasion ability from 56.5 ± 4.8 to 36.3 ± 6.1 (P < 0.05). Conclusion: Down-regulating ACP1 by shRNA reduced the capacity of metastasis of MG-63 cell,which providing a novo-approach to biotherapy of cancer.