Abstract: Objective To investigate the effect possible mechanism of miR-17-92 gene cluster on proliferation and invasion of osteosarcoma (OS) cells. Methods The miR-17-92 gene cluster in OS cells MG-63 and human osteoblast hFOB1.19 was detected by real-time quantitative fluorescence PCR (qRT-PCR). Transfected MG-63 cells were divided into miR-17-92 gene cluster mimic group and negative control group (miR-NC group). The level of miR-17-92 gene cluster, cell proliferation and invasion ability, transforming growth factor beta 1, transforming Growth Factor Beta 1, transforming growth Factor Beta 1, transforming growth factor Beta 1 (TGF-β1), Smad3, matrix metalloproteinase (MMP) -2, and MMP-9 protein levels were compared between the two groups. Results The relative expression levels of miR-17, miR-18a, miR-19a, miR-19b, miR-20 and miR-92 in OS cells MG-63 were significantly higher than those in human osteoblasts hFOB1.19 (P < 0.05); The relative expression levels of miR-17, miR-18a, miR-19a, miR-19b, miR-20 and miR-92 in miR-17-92 gene cluster mimic group were significantly higher than those in miR-NC group (P < 0.05); The OD450 values in miR-17-92 gene cluster mimic group on 1, 2 and 3d were significantly higher than those in miR-NC group (P < 0.05), and the number of invasion cells in miR-17-92 gene cluster mimic group was (65.25±13.51), which were significantly more than those in miR-NC group (40.58±10.34) (P < 0.05); The levels of TGF-β1, Smad3, MMP-2 and MMP-9 in miR-17-92 gene cluster mimic group were significantly higher than those in miR-NC group (P < 0.05). Conclusion The abnormally high expression of miR-17-92 gene cluster in osteosarcoma MG-63 cells can enhance cell proliferation and invasion, and the mechanism may be related to the activation of TGF-β1/Smad3/MMP-9 signaling pathway.