Dihydromyricetin (3, 5, 7, 3′, 4′, 5′-hexahydroxy-2, 3-dihydroflavonol, DMY) isolated from Ampelopsis grossedentata is known to have an anti-proliferative effect in vitro on a few cancer cells. However, the exact mechanisms retain unclear. The aim of this article was to study the effect of DMY on cell invasion of highly metastatic human breast cancer MDA-MB-231 cells, and investigate the possible mechanisms. The anti-proliferation effect of DMY on MDA-MB-231 cells was determined by the MTT assay. The gelatinolytic activity was assessed by gelatin zymography. The mRNA and the protein expression levels of MMP-2/-9 were evaluated by Real-time PCR and Western blot assay, respectively. The effect of DMY on cell invasion was observed by a transwell model. Results indicated that DMY inhibited the proliferation of MDA-MB-231 cells in a dose-dependent manner, and the IC₅₀ value was about 73.6 mg/L after treated by DMY for 48 h. DMY suppressesed gelatinase activity and MMP-2/-9 protein expression levels in a dose-dependent manner, and restrained MMP-2/-9 mRNA expression levels. In addition, DMY inhibited the invasion of MDA-MB-231 cells in a dose-dependent manner without cytotoxicity against the cancer cells. DMY can inhibit proliferation and invasion of MDA-MB-231 cells, and invasion inhibition may be related to the down-regulation of the expression levels of MMP-2/-9 proteins.