Objective：This study aims to determine the function of WNT7b in the progression of malignant melanoma and the underlying mechanism by which it promotes the migration and invasion of melanoma cells. Methods：Intrinsic WNT7b expression level was examined in A875，SK-MEL-28，and A375 cell lines by qRT-PCR and Western blot. The intervention of WNT7b in A375 cell line was performed by transiently transfected with small interfering RNA，and its effect on the cellular function was also analyzed by flow cytometry analysis，wound healing and Transwell assay，respectively. Then Western blot was used to detect the expression of epithelial-mesenchymal transition（EMT）related markers and members of matrix metalloproteinase（MMP）family. Results：WNT7b was expressed in A375，SK-MEL-28 and A875 cell lines，among which A375 presents the highest WNT7b expression. Our cellular study showed that upon knockdown of WNT7b expression in human A375 cell line，the cell cycle was arrested at G1 phase，the cell migration and invasion ability were significantly inhibited. In addition，WNT7b knockdown led to the up-regulation of E-cadherin and down-regulation of N-cadherin，Vimentin and Snail1. Further detection of MMP family members showed that the expression of MMP-2，MMP-7 and MMP-9 was reduced. Conclusion：WNT7b may induce EMT through MMPs in human malignant melanoma cells，thereby promoting cells migration and invasion.