Objective To observe the effect of metadherin/astrocyte elevated gene-1 (MTDH/AEG-1) silencing on the proliferation and metastasis of SGC7901 human gastric cancer cells. Methods The eukaryotic shRNA expression vectors targeting MTDH gene were constructed and transfected into SGC7901 cells. Effects of gene silencing were confirmed by Western blotting. MTT assay was used to detect the effect of MTDH on the proliferation of SGC7901 cells, and TranswellTM assay was employed to detect the effect of MTDH on the migration of SGC7901 cells. Results MTDH-shRNA was constructed and transfected into SGC-7901 cells successfully. After transfection, the level of MTDH protein expression was reduced significantly. Knockdown of MTDH in SGC7901 cells, the abilities of cell proliferation and migration decreased obviously. Conclusion Knockdown of MTDH gene effectively inhibits the proliferation and metastasis of SGC7901 cells.