Objective：This study aims to analyze the expression of miR-1247 in human osteosarcoma cell lines，as well as its effect and mechanism on proliferation and apoptosis of osteosarcoma cells. Methods：qRT-PCR was performed to evaluate expression of miR-1247 in human osteosarcoma cell lines（U2OS，Saos-2 and 143B）and human normal osteoblast cell line（hFOB1.19）. Saos-2 cell line were divided into two groups，miR-1247 group transfected with miR-1247 mimics and EV group transfected with miR-1247 scramble. MTT assay and flow cytometry was used to assess proliferation and apoptosis ability of cells. Western blot was carried out to determine Sox9 and FAM129B proteins expression. Results：miR-1247 expression level in osteosarcoma cell lines was significantly lower than that in normal osteoblast cell line （P < 0.05）. There was no significantly difference in cell proliferation between EV and miR-1247 group after transfect for 0，1，3 d（P > 0.05）. The cell proliferation of miR-1247 group was significantly lower than that of EV group after transfect for 5，7 d（P < 0.05）. The apoptosis rate of miR-1247 group was significantly higher than that of EV group（P < 0.05）. The expression level of SOX9 and FAM129B protein of miR-1247 group was significantly lower than that of EV group（P < 0.05）. Conclusion：Osteosarcoma cell lines showed lower miR-1247 expression compare to normal osteoblast cell line. miR-1247 inhibit proliferation and induce apoptosis in osteosarcoma cell lines via down-regulation of Sox9 and FAM129B proteins.