Objective To determine the in vitro effects of the combination of adriamycin and recombinant human vascular endothelial inhibitor on human osteosarcoma cells. Methods: Human osteosarcoma cells were treated with adriamycin, recombinant human vascular endothelial inhibitor and the combination of the two drugs, and the cytotoxicity was determined by MTT at 24h, 72h and 144h, and the morphological changes were observed by inverted phase contrast microscopy. The cell proliferation activity of recombinant human vascular endothelial inhibitor was inhibited at 72h and 144h by 10μg/ml and 100μg/ml of adriamycin, and the cell proliferation activity of recombinant human vascular endothelial inhibitor was inhibited at 72h by 7.3%-9.2% of osteosarcoma cells. The cells in both the adriamycin and the combination groups showed small cell size, nuclear fragmentation and loss of normal cell morphology, while the cell morphology of recombinant human vascular endothelial inhibitor alone was similar to that of the control group. It was concluded that recombinant human vascular endothelial inhibitor only had a mild inhibitory effect on human osteosarcoma cells in the short term after administration, and recombinant human vascular endothelial inhibitor did not affect the cytotoxic effect of adriamycin on osteosarcoma cells.