Abstract: Objective: To determine the effect of microRNA- 192 inhibitors on the proliferation and apoptosis of human osteosarcoma cell line SOSP- 9607. Methods:MTT assay was used to examine the inhibitory rate of the proliferation of SOSP-9607cells by hsa-miR- 192 inhibitors. Cultured SOSP- 9607cells were divided into two groups: the control group and the experiment group. The control group included two subgroups: the negative control subgroup and the normal control subgroup. In the experiment group, hsa-miR- 192 inhibitors were used to inhibit the activity of miR - 192 . The experiment group included three subgroups with different doses. The apoptosis and the cell cycle were measured by flow cytometry. Cultured SOSP-9607 cells were also divided into two groups: the control group and the experiment group. Results: Hsa-miR-192 inhibitors inhibited SOSP- 9607 cell proliferation in a dose-dependent manner (P<0.01), but no obvious effect was observed on cell proliferation in the control group (P>0.05). With the increase of concentration of inhibitors from 50 nmol/L to 200 nmol/L, the inhibitory rate was increased significantly ( P<0.01). Hsa-miR- 192 inhibitors increased the percentage of cells at G0/G1 phase and decreased the percentage of cells at G 2/M phase and S phase ( P<0.01). The apoptosis ratio in the experiment group was 13.6% ±2.1% , higher than that in the control group (7.1% ±0.5% ,P<0.01). Conclusion:The hsa-miR-192 inhibitors play an important role in the proliferation and apoptosis of SOSP- 9607 cells through down-regulating miR-192 , which may be a promising target for biotherapy of osteosarcoma.